Seminars

TH-Seminar: Prof. Julia Westermayr

MP Department Seminar by Richard A. Wilhelm

MP Department Seminar by Achim Peters

Controlling and Observing Coherent Phonons in Thin van der Waals Materials

Ultrashort laser pulses can induce coherent phonons, where all atoms in the crystal oscillate in phase. Using ultrafast electron diffraction, we can directly image this joint atomic motion in the time domain. [more]

TH-Seminar: Prof. Christopher J. Stein

Investigating supercooled water with laser- and X-ray spectroscopy

Water exhibits a variety of anomalies, some of which are particularly pronounced in the supercooled region. Its specific properties and possible structural and dynamical origins have been extensively studied, leading to the still inconclusive theory that water may exist in two structural motifs at low temperatures. [more]

Workshop on “THz and SFG spectroscopy and related phenomena in Solid-State Physics and Surface Science"

Workshop on “THz and SFG spectroscopy and related phenomena in Solid-State Physics and Surface Science"

Manoeuvring chemical reactions one degree of freedom at a time

The combined use of electric fields, magnetic fields and laser light affords us an ever-increasing level of control over the properties of atoms and molecules, enabling reactivity to be probed as a function of their various degrees of freedom1. Here, we discuss how electrostatic deflection2,3 can be employed to disentangle the reactivity of molecules in different rotational states4, or with different spatial orientation of their constituent atoms5. [more]

Self-Interaction of Polarons Addressed through the Piecewise Linearity Condition

The piecewise linearity condition is a property satisfied by the exact density functional and has been found to yield band gaps in accord with experiment [1,2] when imposed to hybrid functionals. [more]

Recent insights on the generation, transport, and separation of charge carriers in metal oxide photocatalysts

CatLab Lectures 2023/2024
Metal oxide photoelectrodes tend to be cheap, easy to fabricate, and show relatively good (photo)chemical stability in aqueous solutions. This makes them attractive candidates as light absorbers in a variety of photoelectrochemical and photocatalytic applications. However, the energy conversion efficiencies of these absorbers are poor compared to photovoltaic-grade materials. [more]

Towards atomic diffraction through single-layer graphene

Using hydrogen atoms with a velocity of up to 120 000 m/s, we predict a high probability of coherently diffracting atoms through the natural lattice of the crystalline gratings. [more]

Towards the Accurate Simulation of Electrochemical Interfaces by Combining Electron Density and Long-Range Machine-Learning Methods

The accurate study of electrochemical interfaces calls for simulation techniques that can treat the electronic response of metal electrodes under electrostatic perturbations. Despite recent advancements in atomistic machine-learning (ML) methods applied to electronic-structure properties, predicting the non-local behavior of the charge density in electronic conductors remains a majoropen challenge. [more]

Non-equilibrium dynamics of laser-excited electrons in a metal

Femtosecond laser pulses irradiating a solid material induce a cascade of processes starting with the excitation of so-called hot electrons and passing through various relaxation processes. Several scattering mechanisms act on different timescales. At sufficiently high energy densities, phase transitions and ultrafast structural dynamics can be induced.We simulate the dynamics of a large ensemble of excited electrons using complete Boltzmann collision integrals. We consider the excitation of conduction electrons in a metal with visible light. On a femtosecond timescale, the electrons' energy distribution deviates strongly from a Fermi distribution. We extract spectral electron densities within specificenergy windows, and find complex behavior that cannot be matched with a single relaxation time.We show that electron-electron and electron-phonon scattering mutually influence each other during thermalization. For materials with several electronic systems, e.g. itinerant ferromagnets or dielectrics, we observe that temperatures and partial densities can be independent quantitieson picosecond timescales. [more]

Multiscale Studies and Engineering of Surface-Reactive Systems

CatLab Lectures 2023/2024
Tomorrow’s chemicals are facing massive transitions due to the need for an alternative energy input, changing feedstock, limited resources, varying cost structures, etc. Chemical and reaction engineering is in charge for chemical and electrochemical reactions to meet the upcoming business and technical objectives. For simultaneous process-product design, a multiscale understanding provides opportunities to consider phenomena on different time and length scales of the reaction system. [more]

Will a single two-level atom simultaneously scatter two photons?

The interaction of light with a single two-level emitter is the most fundamental process in quantum optics, and is key to many quantum applications. [more]

High-power Ultrafast Moves into the Terahertz Domain

Terahertz Time Domain Spectroscopy (THz-TDS) has become a ubiquitous tool in many scientific fields and is also increasingly deployed in industrial settings. While these systems become more and more mature, efficient and lab-based THz generation methods combining broad bandwidth and high dynamic range (e.g., as provided by high THz average power and correspondingly high repetition rate) remain rare. [more]

Catalyst for Acetylene Hydrogenation - CatLab Approach

CatLab Lectures 2023/2024
The focus will be the catalyst characterization and development in heterogenous catalysis in particular in acetylene hydrogenation. The role of acetylene hydrogenation in industry and future renewable energy approaches will be discussed. [more]

Diatomic Molecules: from hot to ultracold

In this talk I will be discussing a new ultracold molecules experiment that I'm setting up at Durham University. Ultracold molecules offer possibilities for a range of applications from controlled chemistry and testing beyond standard model physics, to quantum simulation. In this talk I will focus on what makes cold molecules promising candidates for these applications, and how we are working towards harnessing power this experimentally. [more]

Uncovering electrocatalysts and electrochemical interfaces in situ at the nanoscale

CatLab Lectures 2023/2024

Theory of Photo- and Electro-luminescence in Scanning Tunneling Microscopy

I will talk about the theoretical perspective on a microscopy technique that combines the atomic-scale resolution of a scanning-tunneling microscope (STM) with optics. [more]

Wet-chemical synthesis and catalytic properties of metal clusters of small atomicity without protecting ligands

Magnetic characterisation of catalysts for energy applications

CatLab Lectures 2023/2024

Following the Dynamics of Nanoparticle Surfaces in Search of New Catalytic Pathways

Understanding mechanisms of work for a wide range of applied nanomaterials begins with identifying “active units” in operating conditions, zooming in on the “active sites” and ends with a model explaining their role for functioning of the material or device. [more]

Ultrafast Dynamics in a Photo-induced Symmetry-breaking Transition

The study of the suppression of an order parameter by an external perturbation and the following recovery of the broken-symmetry phase is a problem relevant to systems even beyond condensed matter physics. In the context of pump-probe experiments, it has been tackled considering the suppression of the charge density wave order parameter in several compounds, and it was found a relevant role played by the fluctuations [1,2]. [more]

Chirality differentiation and manipulation using rotational spectroscopy

Chirality is ubiquitous in nature and involved in many aspects of life, making it an important phenomenon to understand. The enantiomers of chiral molecules have identical physical properties (despite the predicted small contributions due to parity-violating weak interactions), while their chemical and biochemical properties can differ dramatically. Due to these different behaviors, the development of sensitive spectroscopic methods that can differentiate and/or separate molecules of opposite handedness, particularly in complex sample mixtures, are of utmost importance. [more]

Towards State- and Time-Resolved Fluorescence Spectroscopy of Trapped Molecular Ions

  • MP Department Seminar
  • Date: Jan 15, 2024
  • Time: 11:00 AM c.t. - 12:00 PM (Local Time Germany)
  • Speaker: Jascha Lau
  • Otto-Hahn Awardee of the Biological and Medical Section of the MPG and new Group Leader in the Department of Molcecular Physics
  • Location: Haber Villa
  • Room: Seminar Room
  • Host: Department of Molecular Physics
In this talk, I will give an overview of my postdoctoral and doctoral research, with a particular focus on anion photoelectron spectroscopy and infrared fluorescence spectroscopy, as well as the future research direction of my Otto Hahn Group in the Department of Molecular Physics, which will revolve around fluorescence spectroscopy of trapped molecular ions. [more]

Heterogeneous Catalysis as Enabler of Circular Economy

CatLab Lectures 2023/2024
The guidelines of sustainable development require a transformation of today's linear chemical industry with the aim of closed carbon cycles. In this process, renewable energy can be used as an energy/heating source and to provide chemical redox equivalents, e.g. in the form of hydrogen or electrons. Catalysts are essential to enable selective chemo-, bio-, or even electrocatalytic reactions under the dynamic supply of resources. [more]

Time-resolved XPS for molecular electronic movies

Light excitation couples to molecular electrons. The conversion of photon energy into other molecular forms of energy is then determined by a complex interplay of electrons and nuclei, which is out of the scope of the Born-Oppenheimer approximation. [more]

Ultrafast, all-optical, and highly enantiosensitive imaging of molecular chirality

Just like our hands, chiral molecules exist in pairs of opposite “mirror twins” called enantiomers, which behave identically unless they interact with another chiral “object”. Distinguishing them is vital, e.g. as most biomolecules are chiral, but it can also be a challenging task. [more]

The Exact Factorization, a Universal Approach to Non-Adiabaticity

The adiabatic approximation describes the molecular wave function as a single product of a Born-Oppenheimer state and a nuclear wave packet. This approximation is a corner stone of modern quantum chemistry and solid-state physics. It not only makes computations feasible, it also provides us with an intuitive picture of many chemical processes. [more]

Molecular Simulation in the Age of AI

  • ISC and TH Seminar
  • Date: Dec 13, 2023
  • Time: 02:00 PM - 03:30 PM (Local Time Germany)
  • Speaker: Dr. Edward Pyzer-Knapp
  • Head of Research Innovation for UK and Ireland at IBM, Visiting Professor of Industrially Applied AI at the University of Liverpool, and the Editor in Chief for Applied AI Letters.
  • Location: FHI library (building A)
  • Host: ISC and TH Department
The history of chemical discovery has been punctuated by computational and theoretical developments. Evolving from empirical observation, increasingly systematised experimentation allowed for the development of theoretical underpinnings, which in turn afforded the paradigm shifting application of computational techniques, which has since co-evolved with the development of the technologies upon which they are run. Recent years have seen the emergence of data-driven techniques and technologies for building powerful models, appearing to enable us to side-step the requirement for expensive physical simulations – replacing them with highly performant, but black-box alternatives. [more]

Fast electrons and hard X-rays for unravelling atomic-scale dynamics in homogeneous and heterogeneous catalysis

CatLab Lectures 2023/2024
The increasing demand for renewable and low-cost energy motivates intensive research aimed at developing, characterizing and optimizing materials that can efficiently convert (sun) light into usable energy in the form of electricity or chemical fuels. Conventional characterization techniques either lack the spatial resolution necessary to resolve individual atoms, or they lack the temporal resolution required to capture structural rearrangements as they evolve. [more]

Under the Microscope - Spotlighting Materials & Nano Science

Under the Microscope a science communication project dedicated to materials and nano science. Despite the widespread relevance of materials science to everyday life, we feel that dedicated science communication in this area is much rarer than in other fields. [more]

Design and characterization of integrated systems for solar fuel production

Workshop on “Emerging Techniques of Nanospectroscopy Based on Scanning Probe Microscopy"

Synthesis planning, mechanistic analysis and discovery of new reaction classes in the age of computers

  • ISC and TH Seminar
  • Date: Dec 1, 2023
  • Time: 11:00 AM - 12:30 PM (Local Time Germany)
  • Speaker: Bartosz A. Grzybowski
  • Bartosz A. Grzybowski is a Distinguished Professor of Chemistry at UNIST and a Director of the IBS Center for Algorithmic and Robotized Synthesis (CARS). He is also Professor at the Institute of Organic Chemistry, Polish Academy of Sciences. Although he has spent a large fraction of his research career on esoteric problems of self-assembly and non-equilibrium systems, he considers his most impactful discoveries to be in the area of computer-driven synthesis (e.g., the Chematica/Synthia and Allchemy programs).
  • Location: FHI library (building A)
  • Host: ISC and TH Department
After decades of rather unsuccessful attempts, computers are finally making impact on the practice of synthetic chemistry. This change is made possible by the combination of increased computing power and, above all, new algorithms to encode and manipulate synthetic knowledge at various levels, from sequences of full reactions to sequences of mechanistic steps. In my talk, I will illustrate how these advances have enabled completely autonomous planning of multistep syntheses of complex (natural product) targets, how they allow us to elucidate complex reaction mechanisms and, above all, discover new classes of reactions. [more]

Thin film electrocatalysts for long term energy conversion and storage

CatLab Lectures 2023/2024
Electrochemistry plays a pivotal role in our future transition to sustainable energy, particularly for the conversion of electrical into chemical energy in electrolyzers, and the reverse conversion and utilization of the stored energy in batteries and fuel cells. The common challenge in these electrochemical devices is the development of active and durable materials for the catalysis. [more]

Single-molecule imaging and engineering of biological and synthetic molecular motors

  • PC Department Seminar
  • Date: Nov 30, 2023
  • Time: 11:00 AM (Local Time Germany)
  • Speaker: Ryota Iino
  • Institute for Molecular Science, National Institutes of Natural Sciences, Japan
  • Location: Building G
  • Room: 2.06
  • Host: Martin Wolf
Molecular motors, an important class of molecular machines, harness various energy sources to move unidirectionally [1]. The operational principles of molecular motors are distinct from those of man-made macroscopic motors, because they have nanoscale dimensions and generally work in a solution environment where viscosity is dominant. Under these low Reynolds number, overdamped conditions, they cannot rely on inertia to sustain motion. Furthermore, they are continually agitated by random Brownian motion, which provides both challenges and opportunities for the unidirectional motion. [more]
Copper oxide-derived electrocatalysts are reported to have high activity and selectivity for nitrate electrochemical reduction reaction (NO3RR) to ammonia. However, the cause underlying their enhanced NH3 formation, i.e., the active catalytic site, remains unclear. [more]

Applications of ICP-MS in Electrocatalysis Research

CatLab Lectures 2023/2024
Fuel cells and electrolysers require electrocatalysts to minimize losses during energy conversion processes. It is common practice that researchers rely solely on electrochemical methods to test stability in search of novel electrocatalysts. While degradation can be tracked using such methods, they fail when one aims to understand governing degradation mechanisms responsible for the losses in catalyst performance. Complementary physicochemical techniques are required. One such technique is inductively coupled plasma mass spectrometry (ICP-MS) – the main topic of my talk. [more]

Nanoparticles with Cubic Symmetry: Classification of Polyhedral Shapes

The detailed characterization of polyhedral bodies, while a subject of mathematical research since ancient times, has attracted new interest in connection with crystalline nanoparticles (NP). [more]

Efforts of Zhejiang University in advancing clean and sustainable energy conversion

In the presentation, a brief introduction of Zhejiang University (ZJU) and State Key Laboratory of Clean Energy Utilization will be given. An overview of China’s achievements, new goals and new measures in alignment with its Nationally Determined Contributions will be presented. [more]

Lithium, Interfaces & Action: Desiging Solid Battery Materials

Next generation of energy storage devices may largely benefit from fast and solid Li+ ceramic electrolyte conductors to allow for safe and efficient batteries. For those applications, the ability of Li-oxides to engineer their interfaces and be processed as thin film structures and with high control over Lithiation and phases at low temperature is of essence to control conductivity. [more]

Operando Electron Microscopy

CatLab Lectures 2023/2024
Heterogeneous catalysis is considered one of the key technologies in prospective energy conversion scenarios. Yield, efficiency, and lifetime of heterogeneous catalysts will become of utmost importance and the demand of novel high-performance catalysts fulfilling the above- mentioned criteria will rise tremendously. To cope with the prospective high demand for these functional solids, current catalyst development approaches that are based on empirical optimization may become insufficient and should be replaced by knowledge-based catalyst design strategies. [more]

How do chemical bonds break in ultrastrong coupling?

Current efforts for implementing cavity QED in the ultrastrong coupling (USC) regime using molecular vibrations in mid-infrared nanoresonators opens exciting opportunities for exploring novel chemical reactivities that exploit quantum correlations with the electromagnetic vacuum at room temperature. [more]

Microwave absorption: Operando EPR and MCPT as tools to characterize heterogeneous gas phase catalysts

CatLab Lectures 2023/2024
It is well established that many heterogeneous catalysts encounter substantial changes of their properties if comparing the catalyst under turn-over conditions with those found ex-situ. These changes encompass not only structural but also electronic properties rendering a detailed characterization still challenging. A variety of characterization techniques have been developed in recent years toinvestigatecatalytic systems under operando conditions. In this respect it is important to realize that none of these methods allows to obtain a complete picture which requires on the one hand the combination of different techniques and on the other hand knowledge about available techniques and their potential use and their limitations. [more]
First-principles prediction of heterogeneous catalytic performance is challenging due to the complexity of real catalysts and their evolution over time. But even for simple model catalyst surfaces, chemical accuracy (or sufficient accuracy to discriminate the rates of many potentially competing mechanisms) in predictions of reaction energetics on transition metal surfaces is lacking due to difficulties in simultaneously describing metallic states in the catalyst and molecular adsorbate states and the interactions between them. [more]

Model systems in catalysis research

CatLab Lectures 2023/2024
Model catalysts are specifically designed to address the complexity issue in catalysis. Real catalysts are very complex, which makes them a nightmare for scientists seeking to understand how these systems work. Typically, only a small part of the catalyst’s compositional and structural spectrum is relevant for the catalytic process. Consequently, much of the spectral and structural information stems from irrelevant parts of the catalyst, making the identification of relevant components a non-trivial and error-prone task. [more]

Watching Femtosecond Molecular Dynamics using Synchrotrons and X-Ray Free-Electron Lasers

Recording real-time movies of dynamical processes in molecules, as, for example, progressing chemical reactions, has been a driving force for many disciplines in fundamental sciences during the last decades. Comparably new are experimental techniques, that address single molecules in the gas phase and that involve coincident single-particle detection for imaging these dynamics are Coulomb explosion imaging and Photoelectron diffraction imaging. [more]

Modelling catalyst degradation through experiment and computation

CatLab Lectures 2023/2024
Catalysts degrade over time during reactor operation, resulting in loss of activity, as well as selectivity. A variety of physical and chemical phenomena contribute toward catalyst degradation, such as particle growth, coking, poisoning, or chemical reactions between the catalyst and the reaction medium, or between the active material and the catalyst support. Catalyst degradation is not always well-understood, and improving a catalyst's life time is often a trial-and-error process. This lecture will cover the fundamental causes of typical catalyst deactivation phenomena, introduce computational and experimental techniques to analyze catalyst degradation, and demonstrate practical examples to a rational approach to make catalysts more resistant to degradation. [more]
Thin film technology is a key technology in many high tech sectors today and plays a crucial role in the development of photovoltaics. It allows to control of a very broad set of material (e.g.electronic or optical) properties down to the atomic level, yet can be compatible with high-volume low-cost manufacturing. The Catlab project aims to exploit exactly these characteristics of thin film technology for use in catalytic reactions, especially for chemical energy carriers, such as (green) hydrogen and carbon- or nitrogen-based chemicals derived from it. [more]

Electron-Phonon Coupling from First-Principles

For this talk, I will highlight the importance of electron-phonon interaction to describe many experimental phenomena including carrier mobility, phonon-assisted optical absorption, phonon-limited superconductivity, zero-point renormalization, temperature dependence of the bandgaps, electron mass enhancement and polaron liquids.I will show how to derive and efficiently compute electron-phonon interaction from first principles focusing on two manifestations of the electron-phonon coupling: carrier mobility and temperature dependence of the bandgap. [more]

Theory of Higgs Spectroscopy: How to Activate and Detect the Higgs Mode

  • PC Department Seminar
  • Date: Sep 27, 2023
  • Time: 11:00 AM (Local Time Germany)
  • Speaker: Dirk Manske
  • Max Planck Institute for Solid State Research, Stuttgart
  • Location: Building G
  • Room: 2.06
  • Host: Martin Wolf
Higgs spectroscopy is a new and emergent field that allows to classify and determine the superconducting order parameter by means of ultra-fast optical spectroscopy. There are two established ways to activate the Higgs mode in superconductors, namely a single-cycle ‘quench’ or an adiabatic, multicycle ‘drive’ pulse. [more]

Light-Matter Control of Quantum Materials

  • PC Department Seminar
  • Date: Aug 28, 2023
  • Time: 11:00 AM (Local Time Germany)
  • Speaker: Michael Sentef
  • University of Bremen & MPI for the Structure and Dynamics of Matter, Hamburg
  • Location: Building G
  • Room: 2.06
  • Host: Melanie Müller
Advances in time-resolved pump-probe spectroscopies have enabled us to follow the microscopic dynamics of quantum materials on femtosecond time scales. This gives us a glimpse into the inner workings of how complex, emergent functionalities of quantum many-body systems develop on ultrafast time scales or react to external forces. [more]

Gapless Detection of Broadband Terahertz Pulses Using a Metal Surface in Air-based on Field-induced Second-harmonic Generation

We investigate second-harmonic generation (SHG) light from a Pt surface in air under terahertz (THz) pulse irradiation. THz pulse-modulated SHG intensity shows a clear time profile of the THz field. [more]

Optical Probing of Ordering in Solid-State Materials

Symmetry and its breaking sit at the core of condensed matter physics research and determine the ordering and unique functionalities of solid-state materials. Ultrashort light pulses from visible to THz wavelength ranges offer the opportunity to probe and control the electronic, phononic, magnetic, and even time ordering in those materials. [more]

Superradiance in waveguide-coupled atomic ensembles

The power of the light emitted by a single, excited quantum emitter features a characteristic exponential decay. However, the presence of other, identical emitters can substantially alter the decay dynamics of the ensemble. Such collectively enhanced emission is termed superradiance, and has seen increased interest over the last decade due to its potential applications in quantum technology and metrology. [more]

AI-Accelerated Organic Chemistry

AI-accelerated Organic Synthesis is an emerging field that uses machine learning algorithms to improve the efficiency and productivity of chemical synthesis. [more]

Light, Tips and Molecules: SPM on the Path to Direct Nano-Optical Measurements

Exploration of essential photophysics at the level of individual molecules and atoms requires highly specialized optical spectroscopies that work at the very limit of instrument sensitivity or have to use plasmonic nanostructures - in order to overcome the fundamental resolution limits achievable with visible and infrared light. [more]

From Heavy Elements to Peptides: Dynamics, Kinetics, and Thermochemistry

In this presentation, I will review recent studies that utilize guided ion beam tandem mass spectrometry to examine the kinetic energy dependence of ion-molecule reactions. [more]

Polaritonic Metasurfaces

In this talk, I discuss our recent efforts in the context of nano-optics and photonics, with a special emphasis on strong light-matter interactions enabled by excitonic, phononic, electronic and magnonic material responses coupled to engineered metasurfaces. I will discuss our recent theoretical and experimental results in the context of polariton manipulation in these systems, the role of symmetries in their control, and their opportunities for technological advances. The combination of these features with photonic engineering enables giant optical nonlinearities, efficient nanoscale light manipulation and topological wave phenomena. During the talk, I will discuss the exotic light-matter interactions arising in these systems, and their opportunities for wave physics and photonics technologies. [more]

Things MOFs do, a Journey Skirting the Edges of Sanity

Metal Organic Frameworks, or MOFs for short, are a class of materials that consist of organic molecules that link together metal centres to form an ordered, often porous solid. This multi-component nature affords MOFs a great versatility in terms of their internal structure and properties and thus a wide array of potential use cases. Unfortunately, at least from the point of a theorist, their metal-organic nature also makes them a pain in the neck to treat. Especially when comparing theoretical results to experiment it often turns out that MOFs are significantly less well behaved than advertised. [more]
Each local Minimum on the potential energy surfaces corresponds to a stable structure. In a theoretical structure search one typically finds a number of low energy minima that is much larger than the number of experimentally known structures. [more]

2D Silicates from Ultimate Membranes to Robust Ferromagnets

Silica deposited onto late transition metal surfaces spontaneously forms a 2D van der Waals structure constructed of mirror image planes of rings of corner sharing SiO4 tetrahedra with crystalline and amorphous polymorphs possible. The silica can be deposited by an atomic layer deposition (ALD) process, opening the door to applications. [more]

Ultrafast Exciton Dynamics in Moiré Heterostructures: a Time-resolved Momentum Microscopy Study

Transition metal dichalcogenides (TMDs) are an exciting model system to study ultrafast energy dissipation pathways, and to create and tailor emergent quantum phases [1,2]. The versatility of TMDs results from the confinement of optical excitations in two-dimensions and the concomitant strong Coulomb interaction that leads to excitonic quasiparticles with binding energies in the range of several 100 meV. [more]

Hydrogen-Involved Surface Processes on Model Catalysts

The first topic of this talk is focused on the atomic-scale processes of dissociative adsorption and spillover of hydrogen on the single atom alloy catalyst (SAAC) Pd/Cu(111) [1]. The hydrogen spillover on the Cu(111) surface from the Pd site was successfully observed in real-time using infrared reflection absorption spectroscopy (IRAS) at 80 K. The observed chemical shifts of Pd 3d5/2 in X-ray photoelectron spectra (XPS) indicate that H2 is dissociated and adsorbed at the Pd site initially. [more]

Twisted Tessellations - Coherent Control of the Translational and Point Group Symmetries of Crystals with Light

Advances in mid and far-infrared THz sources have created a new paradigm in condensed matter physics: ultrafast structural and functional control through direct lattice excitation. Striking changes in magnetism, metallicity, ferroelectricity, and superconductivity, observed experimentally on ultrafast timescales, have been tied to the anharmonic coupling between pumped infrared-active (IR) phonons and Raman-active phonons via the nonlinear phononics effect. [more]

Semiconductors and Topological Insulators for Infrared and Terahertz Metamaterials

When working in the infrared (IR) or terahertz (THz) spectral ranges, traditional optical materials like gold and silver have extremely large and negative permittivities. This means it is difficult to use these materials for plasmonics or hyperbolic metamaterials, both of which require materials with relatively small and negative permittivities. We must therefore explore alternative materials. In this talk, I will focus on two classes of materials: heavily-doped III-V semiconductors for the IR and topological insulators for the THz. [more]

Rovibronic Transitions in Molecules: Toward an Exact Approach

Molecules exhibit complex structural and dynamical behavior manifested in their degrees of freedom. The common approach to help us understand this complexity is to start with a zero-order approximation. Beyond the zero-order picture, the voyage to explore the molecular world is just about to begin. [more]

Tuning the Polarity of Porous Materials to Impact Adsorption, Diffusion, and Catalysis

Ordered mesoporous (organo)silicas provide a highly tunable platform to modulate the hydrophobicity of their surfaces, through thermal control of surface hydroxyl density as well as the incorporation of organic framework linkers. [more]

Electrochemical surface science of platinum electrodes

This talk will discuss recent insights into the electrochemistry of platinum, highlighting three topics. [more]

Vibrational Circular Dichroism of Molecular Crystals: The Interplay of Symmetry and Chirality

Chiroptical spectroscopy provides an increasingly important, cost-effective alternative for the study of chiral substances in the solid state. In recent years, vibrational circular dichroism (VCD) – the chiral form of IR absorption spectroscopy – has come into focus as a very sensitive probe of molecular conformation and environment. [more]

Single photon hot electron ionization of fullerenes

The separation of the time scales of electronic and nuclear motion in clusters and molecules opens the possibility that the electrons can form a transient and highly excited subsystem coexisting with cold nuclear degrees of freedom. [more]

An Atom's Eye View of Electrochemical Energy Transformations

The transition away from fossil fuels will provide the defining challenge for the next generation of chemists and engineers, and electrochemical technologies are crucial for this transformation. By providing a link between (renewable) electricity sources and chemicals, these technologies allow not only for storage and transportation of energy, but also provide routes to synthesize a wide range of chemicals and materials that today are integrally reliant upon fossil fuels. [more]

Ultrafast Structural Dynamics of Molecular and Biomolecular Systems

Observing molecular dynamics experimentally with both, highest spatial and temporal resolution is one of the biggest challenges in chemistry and biochemistry. Understanding and resolving structure-dynamics relationships will help to further understand molecular function. Few experimental methods allow to resolve multi-scale dynamics and structural information in the same experiment. [more]

A new experiment to measure parity violation in trapped chiral molecular ions

The weak force is predicted to give rise to slightly different structures for left and right-handed chiral molecules, contrary to the common conception that enantiomers are perfect mirror images. [more]

An Experiment to Measure the Electron's Electric Dipole Moment Using an Ultracold Beam of YbF Molecules

The fact that more matter than antimatter has been produced in the early stages of the universe is unexplained and known as the matter-antimatter-asymmetry problem [1]. One precondition is the combined violation of charge conjugation and parity (CP-violation) which is too small in the Standard Model. In almost all theories, CP-violation is also a precondition for the electron to have an electric dipole moment (de). [more]

Coupling the Time-Warp Algorithm with the Graph-Theoretical KMC Approach for Catalysis Simulations on Mega-Lattices and Beyond

Kinetic Monte-Carlo (KMC) simulations have been instrumental in multiscale catalysis studies, enabling the elucidation of the complex dynamics of heterogeneous catalysts and the prediction of macroscopic performance metrics, such as activity and selectivity. However, the accessible length- and timescales are still limited, and handling lattices containing millions of sites with “traditional” sequential KMC implementations becomes prohibitive due to large memory requirements and long simulation times. [more]

THz SASE and seeded FEL based on high brightness photo injector PITZ

The Photo Injector Test Facility at DESY in Zeuthen (PITZ) develops a prototype of an accelerator-based high-power tunable THz source for pump-probe experiments at the European XFEL. [more]

Tailoring Opto-electronic Properties of 2D Semiconductors in van der Waals Heterostructures

The opto-electronic properties of the transition metal dichalcogenides (TMDs) are sensitive to their environment. For example, the presence of graphene in the vicinity of the TMDs modifies their exciton binding energy and the magnitude of the bandgap via external dielectric screening. [more]

Perovskites as Supports for Single-atom Catalysis

Perovskite surfaces attract attention in the catalysis community due to these materials’ promising chemical properties, good ability to separate electron-hole pairs in light harvesting, and the presence of ferroelectricity in many perovskites. While perovskites possess a unique set of interesting bulk properties, their surfaces are much less understood; the main open questions are their structural stability and associated chemical reactivity and catalytic selectivity. [more]

Fully Quantum (Bio)Molecular Simulations: Dream or Reality?

The convergence between accurate quantum-mechanical (QM) models (and codes) with efficient machine learning (ML) methods seem to promise a paradigm shift in molecular simulations. Many challenging applications are now being tackled by increasingly powerful QM/ML methodologies. These include modeling covalent materials, molecules, molecular crystals, surfaces, and even whole proteins in explicit water (https://arxiv.org/abs/2205.08306). [more]

Laser spectroscopy of radioactive atoms and molecules at CRIS-ISOLDE

MP Seminar
Precision experiments based on heavy and polar diatomic molecules have been proposed as a promising pathway to pin down the level of fundamental-symmetry violations in the Universe. [more]

Constructing Defect Phase Diagrams from Ab Initio Calculations

Thermodynamic bulk phase diagrams have become the roadmap used by researchers to identify alloy compositions and process conditions that result in novel materials with tailored microstructures. [more]

Ultrafast molecular chirality: a topological connection

I will describe our very recent results on marrying chiral and topological properties in ultrafast electronic response of chiral molecules in gas phase and show that it brings such benefits as new highly efficient (not relying on interaction with magnetic field) and robust chiral observables, in contrast to standard chiroptical methods. [more]

New ’Low-Cost’ Electronic Structure Methods for Large Systems

All widely used semi-empirical quantum chemical methods like PM6, DFTB, or GFN-xTB are formulated in a (almost) minimal basis set of atomic orbitals, which limits the achievable accuracy for many important chemical properties. [more]

Pathways to Enhance Electrochemical CO2 Reduction Identified Through Multi-Scale Modeling Pathways to Enhance Electrochemical CO2 Reduction Identified Through Multi-Scale Modeling

Multi-physical transport processes on multiple scales are occurring in electrochemical devices and components for CO2 electroreduction. These coupled transport processes determine the local environment in the catalyst layer and subsequently also the reaction rates at the catalytic sites. [more]

Structure and Electronic Properties of Ultrathin Indium Films on Si(111)

Ultrathin metal films on atomically flat semiconductor substrates have been of great interest to investigate physical properties of two-dimensional (2D) metals. Indium-adsorbed Si(111) surfaces are one of the most explored metal/semiconductor systems. [more]

Four short presentations around the topic ISSP

Dr. Adris Anspoks: Short overview about ISSP // Dr. Aleksejs Kuzmins: X-ray absorption spectroscopy // Dr. Anatolijs Šarakovskis: overview about their activities in spectroscopy // Dr. Gints Kučinskis: Electrochemistry & batteries [more]

Solid-state NMR spectroscopy: Chemical shift and other parameters as structural and reactivity descriptors

Modern Methods in Heterogeneous Catalysis Research
Modern Methods in Heterogeneous Catalysis Research. A series of independent lectures around the classical fundamentals of heterogeneous catalysis, such as adsorption, kinetics, structural and surface analysis, and the challenges of thin film technology, such as material development and methods of modern thin film analysis. [more]

Acetylene semi-hydrogenation on intermetallic compounds

Modern Methods in Heterogeneous Catalysis Research
Modern Methods in Heterogeneous Catalysis Research. A series of independent lectures around the classical fundamentals of heterogeneous catalysis, such as adsorption, kinetics, structural and surface analysis, and the challenges of thin film technology, such as material development and methods of modern thin film analysis. [more]

(Electro)catalytic model systems

Modern Methods in Heterogeneous Catalysis Research
Modern Methods in Heterogeneous Catalysis Research. A series of independent lectures around the classical fundamentals of heterogeneous catalysis, such as adsorption, kinetics, structural and surface analysis, and the challenges of thin film technology, such as material development and methods of modern thin film analysis. [more]

Fully-atomistic Light-driven Dynamics in Plasmonic Cavities and Interfaces

The study of confined fields in plasmonic nanocavities and their interaction with molecules and nanostructures is an area of research with vast applications, including enhanced spectroscopy techniques as well as photoinduced/photocatalytic non-equilibrium phenomena. From the theoretical perspective, either classical electromagnetic models or atomistic/quantum descriptions are usually considered. However, in many cases these models ignore the electronic and nuclear quantum effects arising from the chemical nature and dynamics of a junction, such as tunneling, adsorption geometry, structure of the interface, vibrations, etc., or include them only approximately. Hence, a full quantum dynamical description is sometimes inescapable. [more]

Synchrotron-based x-ray spectroscopy methods and experiments for in situ and operando investigations

Modern Methods in Heterogeneous Catalysis Research
Modern Methods in Heterogeneous Catalysis Research. A series of independent lectures around the classical fundamentals of heterogeneous catalysis, such as adsorption, kinetics, structural and surface analysis, and the challenges of thin film technology, such as material development and methods of modern thin film analysis. [more]

In situ studies of Cu catalysed CO2 electroreduction bysoft X-ray STXM and spectro-ptychography

Soft X-ray scanning transmission microscopy (STXM) is a powerful tool for nanoscale materials analysis. [more]

X-ray scattering methods for operando studies of catalysts

Modern Methods in Heterogeneous Catalysis Research
Modern Methods in Heterogeneous Catalysis Research. A series of independent lectures around the classical fundamentals of heterogeneous catalysis, such as adsorption, kinetics, structural and surface analysis, and the challenges of thin film technology, such as material development and methods of modern thin film analysis. [more]
Modern Methods in Heterogeneous Catalysis Research. A series of independent lectures around the classical fundamentals of heterogeneous catalysis, such as adsorption, kinetics, structural and surface analysis, and the challenges of thin film technology, such as material development and methods of modern thin film analysis. [more]

Synthesis of nanostructured films by templating approaches

Modern Methods in Heterogeneous Catalysis Research
Modern Methods in Heterogeneous Catalysis Research. A series of independent lectures around the classical fundamentals of heterogeneous catalysis, such as adsorption, kinetics, structural and surface analysis, and the challenges of thin film technology, such as material development and methods of modern thin film analysis. [more]

Surprising Elements of Light

Light-driven chemical reactions power all life on earth and photochemistry has been intensely studied for more than a century, but light continues to provide surprising possibilities in driving and monitoring chemical reactions. [more]

In-situ transmission electron microscopy in heterogeneous catalysis

Modern Methods in Heterogeneous Catalysis Research
Modern Methods in Heterogeneous Catalysis Research. A series of independent lectures around the classical fundamentals of heterogeneous catalysis, such as adsorption, kinetics, structural and surface analysis, and the challenges of thin film technology, such as material development and methods of modern thin film analysis. [more]

Multi-Scale Modeling of Heterogeneous Catalysis

Modern Methods in Heterogeneous Catalysis Research
Modern Methods in Heterogeneous Catalysis Research. A series of independent lectures around the classical fundamentals of heterogeneous catalysis, such as adsorption, kinetics, structural and surface analysis, and the challenges of thin film technology, such as material development and methods of modern thin film analysis. [more]

Magnetism from First-principles

Development and engineering of new magnetic materials is one of the main goals in modern condensed matter physics. Thereby, first-principles simulations play a significant role in the design of new materials. Nowadays first-principles methods based on the density functional theory can provide very accurate information about electronic and magnetic properties of realistic systems and has become a major supplement and alternative to the experiment. [more]

Functional thin films and electrocatalysts by a soft molecular precursor approach

Modern Methods in Heterogeneous Catalysis Research
Modern Methods in Heterogeneous Catalysis Research. A series of independent lectures around the classical fundamentals of heterogeneous catalysis, such as adsorption, kinetics, structural and surface analysis, and the challenges of thin film technology, such as material development and methods of modern thin film analysis. [more]

Polarons Imaged in Real Space by Combined AFM/STM

Polarons [1] are quasiparticles that form in ionic lattices due to the interaction of excess charges with lattice distortions. This leads to a spatial confinement of the charge and appearance of many novel phenomena. In past decades, polarons turned out to play an important role in electrical transport, optical properties, organic electronics, catalysis, or in exotic materials properties such as colossal magnetoresistance or high-Tc superconductivity. [more]

Kinetic analysis and digital catalysis

Modern Methods in Heterogeneous Catalysis Research
Modern Methods in Heterogeneous Catalysis Research. A series of independent lectures around the classical fundamentals of heterogeneous catalysis, such as adsorption, kinetics, structural and surface analysis, and the challenges of thin film technology, such as material development and methods of modern thin film analysis. [more]

Learning Chemistry from a Computer: Recent Applications of Automatic Mechanism Generation for the Microkinetics of CO2 Methanation on Nickel

Microkinetic mechanisms in heterogeneous catalysis can be incredibly complex, and the development of these mechanisms raises many problems. How do you determine which species and reactions to include? How do you obtain the corresponding parameters? [more]

Fully Quantum (Bio)Molecular Simulations: Dream or Reality?

The convergence between accurate quantum-mechanical (QM) models (and codes) with efficient machine learning (ML) methods seem to promise a paradigm shift in molecular simulations. Many challenging applications are now being tackled by increasingly powerful QM/ML methodologies. These include modeling covalent materials, molecules, molecular crystals, surfaces, and even whole proteins in explicit water (https://arxiv.org/abs/2205.08306). [more]

Multiphase chemistry in cold parts of the atmosphere:Supporting field and modeling scientists with results from X-ray excited photoelectron spectroscopy

AC Seminar
Snow may hold impurity deposits, such as sea salt aerosol, which show vivid chemistry. Snow's porosity guarantees the efficient gas exchange of reaction products with the overlaying air. That snow thus acts as a chemical reactor on Earth with impacts on air quality, climate, and geochemical cycles has long been recognized. X-ray excited electron spectroscopy at near ambient pressure offers the possibility to investigate the underlying processes at surfaces of atmospheric relevance with high sensitivity and chemical specificity. This approach thus fills a unique gap in atmospheric science.Here, I will present the results of our work at the Swiss Light Source tackling 2 seemingly simple questions: 1) At which temperature do aqueous solutions freeze, and 2) How do acidic trace gases dissociate at ice surfaces? [more]

Collective States in Self-assembled Nanomaterials for New Functionalities in Vibrational Spectroscopy and Light-matter Coupling

Collective states are key to understand properties of materials across different length scales. In my talk, I will give an overview of different functionalities that emerge from collective states, with prospects for vibrational spectroscopy and engineering material properties with light. [more]
Modern Methods in Heterogeneous Catalysis Research. A series of independent lectures around the classical fundamentals of heterogeneous catalysis, such as adsorption, kinetics, structural and surface analysis, and the challenges of thin film technology, such as material development and methods of modern thin film analysis. [more]

Bridging scales from surface science to atmospheric chemistry and climate

Joint Seminar of AC and Theory
The development of ambient pressure X-ray photoelectron spectroscopy has from the beginning been motivated and justified by the context of atmospheric sciences, apart from other areas of fundamental and applied surface science. This has come in parallel with the recognition of important surface catalyzed processes in the stratosphere that are essential in ozone destruction. [more]

Picosecond Interfacial Dynamics in Crowded Lipid Membranes Probed with Ultrafast 2D Infrared Spectroscopy

Lipid membranes are much more than barriers between cell compartments, they are integral components of the cell involved in key functions such as signaling, transport, and sensing. Membranes are composed of hundreds of different lipid species and contain thousands of proteins. The biophysical implications of membrane heterogeneity are not fully understood. Our group uses 2D IR spectroscopy to probe the local hydrogen-bond dynamics at the lipid-water interface. [more]

Electron Paramagnetic Resonance for Catalysis Research

Modern Methods in Heterogeneous Catalysis Research
Modern Methods in Heterogeneous Catalysis Research. A series of independent lectures around the classical fundamentals of heterogeneous catalysis, such as adsorption, kinetics, structural and surface analysis, and the challenges of thin film technology, such as material development and methods of modern thin film analysis. [more]

Quantum control of ultracold ion-atom collisions

Hybrid systems of laser-cooled trapped ions and ultracold atoms combined in a single experimental setup have recently emerged as a new platform for fundamental research in quantum physics and chemistry [1]. Reaching the ultracold s-wave quantum regime has been one of the most critical challenges in this field for a long time. Unfortunately, the lowest attainable temperatures in experiments using the Paul ion trap are limited by the possible rf-field-induced heating related to the micromotion. [more]

Probing Electronic Structure and Magnetism in Low Dimensionality - An Experimental Approach

The ever-growing need for next-generation electronic and magnetic devices calls for new solutions for the engineering of quantum materials, in terms of miniaturization, energy consumption and speed compared to reference benchmarks, e.g. 18 ps for the Larmor magnetization switching. A new paradigm has emerged: the effect of the decrease of dimensionality in magnetic materials is recently being given a large deal of attention. [more]

Towards STM of catalytic reactions

CatLab Highlight Lecture
Scanning tunneling microscopy (STM) regularly offers atomic resolution, can work at high pressures and only interacts weakly with matter - seemingly perfect conditions for gaining access to the microscopic processes on a catalyst surface. On the other hand, the number of examples in which working catalysts have actually been imaged with the STM has remained small. [more]

Chemical Physics far from equilibrium

CatLab Highlight Lecture
In this talk, I will discuss recent examples from electrochemistry in which the system’s behavior is ‘more than the sum of its parts’ and nonlinear interactions generate complex forms of organization. Thereby, I will highlight general conditions that generate certain types of cooperative phenomena. Experimental examples range from electrocatalytic reactions, to the electrooxidation of photoelectrodes. The patterns forming can be understood in the framework of ‘many particle models’ with nonlinear and nonlocal interaction between the particles, as they are often found in electrochemical systems. [more]

Facing the Climate Challenge - Tasks and Opportunities for Industrial Oxidation Catalysis

Modern Methods in Heterogeneous Catalysis Research
Modern Methods in Heterogeneous Catalysis Research. A series of independent lectures around the classical fundamentals of heterogeneous catalysis, such as adsorption, kinetics, structural and surface analysis, and the challenges of thin film technology, such as material development and methods of modern thin film analysis. [more]

Investigating Ultrafast Electron and Phonon Dynamics at the Atomic Scale

Electrons, phonons, and their mutual interactions are crucial for the complex phenomena in strongly correlated materials. In this talk, I will show that electron and phonon dynamics can be investigated at the atomic scale by combining THz pump-probe spectroscopy and a scanning tunneling microscope (STM) [1,2]. [more]

Thin film technolgy meets catalysis: Focus on Thin film Growth and Properties

Modern Methods in Heterogeneous Catalysis Research
Modern Methods in Heterogeneous Catalysis Research. A series of independent lectures around the classical fundamentals of heterogeneous catalysis, such as adsorption, kinetics, structural and surface analysis, and the challenges of thin film technology, such as material development and methods of modern thin film analysis. [more]

THz-VUV Ellipsometry and THz Electron Paramagnetic Resonance Ellipsometry Characterization of SiC and Other Wideband Gap and Ultrawideband Gap Materials

The control over electrical conductivity is critical key to enabling gallium oxide and related materials for high power electronic devices. Understanding the influence of dopants and defects onto the electrical and electronic properties is therefore of paramount importance [1]. Identifying defects and their local electronic properties remains a challenge. [more]

Ultrafast Electron Dynamics in Quasi-two-dimensional Quantum Materials

Quantum materials are solids with tantalizing properties arising from special symmetry, dimensionality, topology, and many-body interactions between elementary degrees of freedom (charge, spin, orbital, and lattice). Gaining a microscopic understanding of quantum materials is critical as it implies the possibility of designing materials with desirable properties. [more]

DFTB+, the Fast Way of Quantum Mechanical Simulations

The Density Functional Tight Binding (DFTB) method [1] is an approximate Density Functional Theory (DFT) based framework, which allows for quantum mechanicalsimulations of large systems being typically two or three orders of magnitudefaster than comparable ab initio DFT calculations. [more]

Operando SXRD/XAS studies of CoOx epitaxial thin films for OER electrocatalysis

Cobalt oxides are among the best earth abundant catalysts for the oxygen evolution reaction (OER) in alkaline and neutral electrolytes. We have undertaken operando studies of two dimensional epitaxial cobalt oxide films [1-2] to gain insights into some questions that remain in debate. [more]

The Value of Information: From Statistics to Algorithms

A fundamental question in data science is: how much information can one extract from the data that one collects? [more]

Quantum-Chemical Methods for Large Systems: Low-, Linear-, and Sublinear-Scaling Methods

An overview of our recently developed low-, linear-, and sublinear-scaling methods ranging from HF, DFT, MP2 to RPA is given. These methods allow — also in combination with graphics processing units (GPUs) — for the efficient description of large systems at QM and QM/MM levels, where QM spheres with typically 500-1000 atoms are necessary for reliable studies. [more]

New Concepts in Battery and Solid Electrolyte Design

Solid electrolytes (SEs) are a key component of all-solid-state batteries (ASSBs), which promisehigher energy density along with safer operation compared to commercial Li ion batteries. As theASSB technology matures, research in the field gravitates towards questions regarding stability,scalability, and integration of solid electrolytes into ASSBs with extended cycle life. [more]

Design of Novel Hybrid and Solid State Battery Materials

Next generation of energy storage devices may largely benefit from fast and solid Li+ ceramic electrolyte conductors to allow for safe and efficient batteries and fast data calculation. For those applications, the ability of Li-oxides to be processed as thin film structures and with high control over Lithiation and phases at low temperature is of essence to control conductivity. [more]

Lightwave-Driven Scanning Tunneling Spectroscopy for Ultrafast Surface Science on the Atomic Scale

The development of novel nanoscale systems with technologically relevant properties has created a demand for powerful experimental technique’s capable of extreme spatio-temporal resolution. Scanning tunneling microscopy (STM) has become an era-defining surface characterization tool capable of extracting the local density of states (LDOS) with ångström-scale spatial resolution. [more]

Understanding of Energy Transfer Dynamics in Luminescent Eu(III) Complex Doped Host-Guest Film

Trivalent europium (Eu(III)) complexes are expected to be used as light-emitting materials such as organic light emitting diodes (OLEDs) because of their high color purity. The complexes are sensitized by the antenna effect, utilizing energy transfer from antenna ligands to a metal center. In the emitting layer of OLEDs, guest emitters are doped in host molecules, and intermolecular energy transfer also occurs. [more]

Solving Electrochemistry Puzzles by First-Principles Multi-Scale Modeling

Electrochemistry has become the most-promising prospect towards a sustainable energy landscape. Still, most processes have not been optimized to a level that could compete with fossil fuels. Consequently, substantial optimization of electrode materials, electrolytes and electrochemical cells is required on all size scales to quickly reach the industrially desired performance. [more]

Emergent Electronic and Spin States Revealed by Spin Resolved Scanning Tunneling Spectroscopy

  • FHI/IMS Joint Online Seminar
  • Date: Jul 21, 2022
  • Time: 10:00 AM (Local Time Germany)
  • Speaker: Prof. Sujit Manna
  • Department of Physics, Indian Institute of Technology Delhi
Under special conditions, a fermion in a superconductor can separate in space into two parts known as Majorana zero modes (MZM), which are immune to decoherence from local noise sources and are attractive building blocks for quantum computers. Promising experimental progress has been made to synthesize topological superconductors that demonstrate Majorana zero modes in materials with strong spin–orbit coupling proximity coupled to superconductors. [more]

Understanding the Birth of the Catalyst during Pyrolysis Using Synchrotron X-rays

Transition metal-nitrogen-carbon materials (M-N-C catalysts) are promising electrocatalysts in electrochemical applications. High temperature treatment in inert environment (pyrolysis) is the most common method for the synthesis of M-N-C catalysts and critical to achieve high electrocatalyst activity and electronic conductivity. [more]

New Generation of Atomically Dispersed Electrocatalysts

Platinum Group Metal-free (PGM-free) catalysts have been extensively developed for both Proton Exchange Membrane (PEM) and Alkaline Exchange Membrane (AEM) fuel cells aiming automotive, stationary and portable applications. In this lecture we will address the critical challenges that our team has faced on the way to practical application of such catalysts. [more]

Understanding Correlation Among Electron-Phonon-Spin Degree of Freedom in Advanced Molecular Optoelectronics

  • IMS-FHI Joint Online Seminar
  • Date: Jul 4, 2022
  • Time: 10:00 AM (Local Time Germany)
  • Speaker: Kiyoshi Miyata
  • Department of Chemistry, Kyushu University
  • Host: Takashi Kumagai
Microscopic understanding of exciton and carrier physics in molecular materials for optoelectronics is a great challenge because of their complexity resulting from strong electron-phonon coupling and perhaps interaction to spin degree of freedom; [more]

The End of Ab Initio MD

A new computational task has been defined and solved over the past 15 years for extended material systems: the analytic fitting of the Born-Oppenheimer potential energy surface as a function of nuclear coordinates under the assumption of medium-range interactions, 5 ~ 10 Å. [more]

Single-Molecule Studies of Dissociation Reactions of O2 Molecules on Ag(110) by Electrons, Holes, and Localized Surface Plasmons

  • PC Department Online Seminar
  • Date: Jun 27, 2022
  • Time: 10:00 AM (Local Time Germany)
  • Speaker: Emiko Kazuma
  • Department of Applied Chemistry, The University of Tokyo
  • Host: Akitoshi Shiotari
A mechanistic understanding of the dissociation of O2 molecules adsorbed on metal surfaces is crucial not only for the precise control of oxidation reactions but also for the development of various heterogeneous oxidation catalysts. [more]

FHI Library Workshop: Open Access & Information Resources

This interactive workshop will introduce available options for making your research outputs open access. Discover which publishing fees are paid centrally or by the FHI library and get practical tips on how to adopt open access practices in your research area. Furthermore, you will get an overview of useful search tools. More details on how to join the workshop will be announced by e-mail or contact the library team.

Machine Learning (ML) for Simulating Complex Energy Materials with Non-Crystalline Structures

Many materials with applications in energy materials, e.g., catalysis or batteries are non-crystalline with amorphous structures, chemical disorder, and complex compositions, which makes the direct modelling with first principles methods challenging. To address this challenge, we developed accelerated sampling strategies based on ML potentials, genetic algorithms, and molecular-dynamics simulations. [more]
Fluxionality, or the presence of and interconversion between multiple possible energetic configurations, is vital for understanding a catalyst as it operates under actual reaction conditions. [more]

Chemical challenges facing scalable hydrogen production with alkaline membrane electrolyzers

Commercialized membrane electrolyzers use acidic proton exchange membranes (PEMs). These systems offer high performance but require the use of expensive precious-metal catalysts such as IrO2 and Pt that are nominally stable under the locally acidic conditions of the ionomer. [more]

Hot Electrons in Surface Chemistry: From Molecular Scattering to Plasmonic Chemistry

Nonadiabatic effects that arise from the concerted motion of electrons and atoms at comparable energy and time scales are omnipresent in thermal and light-driven chemistry at metal surfaces. [more]

Water Flows in Carbon Nanochannels, from Carbon Memories to Quantum Friction

The emerging field of nanofluidics explores the molecular mechanics of fluids. This world of infinitesimal fluidics is the frontier where the continuum of fluid dynamics meets the atomic nature of matter, or even its quantum nature. Nature fully exploits the fluidic oddities at the nanoscale and it is capable of breath-taking technological feats using a fluidic circuitry made of multiple biological channels, such as ionic pumps, proton engines, ultra-selective pores, stimulable channels, ... [more]

Dynamic catalytic interfaces: ensembles of metastable states break the rules of catalysis

I will show that dynamic catalytic interfaces exhibit great structural fluxionality in conditions of catalysis, and populate many distinct structural and stoichiometric states, which form a statistical ensemble. [more]

FHI Library Workshop: Databases

Our workshop will help you to select and apply the most appropriate resources and tools for your research. Learn more on how to quickly find and analyze relevant scientific literature. The two databases Web of Science and SciFinder will be presented and discussed in detail. More details on how to join the workshop will be announced by e-mail or contact the library team.

Sub-molecular Imaging of Light-matter Interaction

  • FHI/IMS Joint Online Seminar
  • Date: May 9, 2022
  • Time: 11:00 AM (Local Time Germany)
  • Speaker: Anna Rosławska
  • Université de Strasbourg, CNRS, IPCMS
  • Host: Melanie Müller
Light-matter interaction plays a crucial role in the quantum properties of light emission from single molecules, and in electron-to-photon and photon-to-electron energy conversions. Such mechanisms are usually probed using optical methods, which are, however, spatially limited by diffraction to a few hundred nanometers. [more]

Machine Learning at the Atomic Scale: From Structural Representations to Chemical Insights

When modeling materials and molecules at the atomic scale, achieving a realistic level of complexity and making quantitative predictions are usually conflicting goals. Data-driven techniques have made great strides towards enabling simulations of materials in realistic conditions with uncompromising accuracy. [more]

On-Surface Chemistry of Helicenes

  • Department Online Seminar
  • Date: May 2, 2022
  • Time: 11:00 AM (Local Time Germany)
  • Speaker: Karl Heinz Ernst
  • EMPA, Dübendorft, Switzerland
  • Host: Martin Wolf
Surfaces functionalized with helicenes are of interest for chiroptical electronic devices or for electron-spin filtering. While self-assembled layers facilitate studying interesting phenomena, covalently linked chiral modified materials would be much more robust and therefore better suited for applications. [more]
The interaction of adsorbates on solid surfaces with light is central to surface spectroscopy, surface photochemistry, and non-adiabatic surface science in general. In the present contribution, light-driven molecular adsorbates will be modelled (mostly) by ab initio molecular dynamics. A few examples will be highlighted: [more]

Ultrafast Lattice Dynamics and Microscopic Energy Flow in Ferromagnetic Metals and in an Anisotropic Layered Semiconductor

  • PC Department Online Seminar
  • Date: Apr 22, 2022
  • Time: 11:00 AM (Local Time Germany)
  • Speaker: Daniela Zahn
  • FHI Department PC
  • Host: Ralph Ernstorfer
In this talk, I will give an overview of my PhD thesis, focusing on two topics: lattice dynamics in black phosphorus and ultrafast energy flow in 3d ferromagnets. The layered semiconductor black phosphorus exhibits a peculiar structure with in-plane anisotropy. Here, we use femtosecond electron diffraction to access the lattice response to laser excitation. The optical excitation and subsequent electron-phonon coupling lead to a pronounced non-thermal state of the lattice, which is characterized by a transiently reduced anisotropy of the atomic vibrations. On timescales of tens of picoseconds, thermal equilibrium is restored via phonon-phonon coupling [1,2]. Our results yield insights into both electron-phonon and phonon-phonon coupling and provide pathways to control the timescale of lattice thermalization in black phosphorus. [more]

Femtosecond Infrared Spectroscopy of Photoinduced Intermolecular H+ Transport

Ultrafast intermolecular proton (H+) transport pathways of the bifunctional photoacid 7-hydroxyquinoline (7HQ) in polar protic methanol solvent are examined with femtosecond UV-pump/IR-probe spectroscopy. Following electronic excitation, 7HQ can be converted simultaneously into a strong acid and a strong base. [more]

FHI Library Online Workshop: Information Resources & Open Access

This interactive online workshop will introduce available options for making your research outputs open access. Discover which publishing fees are paid centrally or by the FHI library and get practical tips on how to adopt open access practices in your research area. Furthermore, you will get an overview of useful search tools. More details on how to join the workshop will be announced by e-mail or contact the library team.

Time- and Angle-Resolved Photoemission Study on Bulk VSe2

  • PC Department Online Seminar
  • Date: Apr 4, 2022
  • Time: 11:00 AM (Local Time Germany)
  • Speaker: Dr. Wibke Bronsch
  • Elettra - Sincrotrone Trieste, Trieste, Italy
  • Host: Chris Nicholson
By means of time- and angle-resolved photoemission spectroscopy (tr-ARPES), we investigate the effect of the charge density wave (CDW) phase transition on the equilibrium and out-of-equilibrium electronic properties of the transition metal dichalcogenide VSe2. [more]

Machine-Learning Potentials: The Accurate, the Fast, and the Applied

Data-driven algorithms ("machine learning") are increasingly used in science and engineering for analysis, prediction, and control, enabling new insights and applications. A promising example are first-principles simulations of the dynamics of atomistic systems. [more]

FHI Library Online Workshop: Databases

Our interactive online workshop will help you to select and apply the most appropriate resources and tools for your research. Learn more on how to quickly find and analyze relevant scientific literature. The two databases Web of Science and SciFinder will be presented and discussed in detail. More details on how to join the workshop will be announced by e-mail or contact the library team.

Library Workshop on Reference Management Systems

This interactive online workshop will introduce available options for making your research outputs open access. Discover which publishing fees are paid centrally or by the FHI library and get practical tips on how to adopt open access practices in your research area. Furthermore, you will get an overview of useful search tools. More details on how to join the workshop will be announced by e-mail or contact the library team.

In Silico Design of Single-Atom- and Highly-Dilute-Alloy Catalysts: Success Stories and Opportunities for Innovation

Catalysis is undoubtedly at the heart of the chemical industry: out of all chemicals manufacturing processes, 85-90% are catalytic and about 80-85% thereof employ heterogeneous catalysts. Yet, developing catalysts for given applications is non-trivial, necessitating empirical and resource-intensive trial-and-error experimentation. Theory and simulation, on the other hand, can provide fundamental insight into the mechanisms underpinning catalytic function, and guide the design of catalytic materials for applications of practical interest. [more]

Near-field Optical Microscopy and its Recent Advances: High Speed Imaging and Broadband Measurements

Near-field optical microscopy (aperture-less type) enables optical analysis and imaging with the nanoscale spatial resolution owing to light field localized at a nanometric volume at a plasmonic tip apex. It has been recognized as a powerful analytical technique for a few decades since its invention, and has still shown tremendous progress, contributing to a wide variety of scientific fields. Its spatial resolution, for example, has been drastically improved in recent years, which now goes down to the single molecular level. [more]

FHI Library Online Workshop: Information Resources & Open Access

This interactive online workshop will introduce available options for making your research outputs open access. Discover which publishing fees are paid centrally or by the FHI library and get practical tips on how to adopt open access practices in your research area. Furthermore, you will get an overview of useful search tools. More details on how to join the workshop will be announced by e-mail or contact the library team.

Analysis of thin films by in-situ IR spectroscopy

CatLab Lectures Modern Methods in Heterogeneous Catalysis Research
Modern Methods in Heterogeneous Catalysis Research. A series of independent lectures on basic principles and new challenges in catalysis research. The lecture series is aimed at PhD students and scientists who are interested in interfacial phenomena and the design and investigation of functional 3D and 2D materials. [more]

Deposition and operando analysis techniques for solar fuels

CatLab Lectures Modern Methods in Heterogeneous Catalysis Research
Modern Methods in Heterogeneous Catalysis Research. A series of independent lectures on basic principles and new challenges in catalysis research. The lecture series is aimed at PhD students and scientists who are interested in interfacial phenomena and the design and investigation of functional 3D and 2D materials. [more]

X-ray microscopy

CatLab Lectures Modern Methods in Heterogeneous Catalysis Research
Modern Methods in Heterogeneous Catalysis Research. A series of independent lectures on basic principles and new challenges in catalysis research. The lecture series is aimed at PhD students and scientists who are interested in interfacial phenomena and the design and investigation of functional 3D and 2D materials. [more]

Strong Coupling and Extreme Anisotropy in Infrared Polaritonic Media

  • PC Department Online Seminar
  • Date: Jan 24, 2022
  • Time: 11:00 AM (Local Time Germany)
  • Speaker: Dr. Joshua D. Caldwell
  • Vanderbilt University, Nashville, Mechanical Engineering Dept.
The field of nanophotonics is based on the ability to confine light to sub-diffractional dimensions. In the infrared, this requires compression of the wavelength to length scales well below that of the free-space values. While traditional dielectric materials do not exhibit indices of refraction high enough in non-dispersive media to realize such compression, the implementation of polaritons, quasi-particles comprised of oscillating charges and photons, enable such opportunities. [more]

Diffraction methods and residual stress analysis of thin layers

CatLab Lectures Modern Methods in Heterogeneous Catalysis Research
Modern Methods in Heterogeneous Catalysis Research. A series of independent lectures on basic principles and new challenges in catalysis research. The lecture series is aimed at PhD students and scientists who are interested in interfacial phenomena and the design and investigation of functional 3D and 2D materials. [more]

Data-Enabled Materials Structure-Property-Synthesizability Predictions

The constant demand for new functional energy materials calls for efficient strategies to accelerate the materials discovery. In addressing this challenge, materials informatics deals with the use of data, computations, and machine learning (complementary to experts’ intuitions) to establish the materials structure-property relationships and to make a new functional discovery in a rate that is significantly accelerated. [more]

Properties of thin films and their interfaces as revealed by X-ray spectroscopies

CatLab Lectures Modern Methods in Heterogeneous Catalysis Research
Modern Methods in Heterogeneous Catalysis Research. A series of independent lectures on basic principles and new challenges in catalysis research. The lecture series is aimed at PhD students and scientists who are interested in interfacial phenomena and the design and investigation of functional 3D and 2D materials. [more]

Surface states conduction measurements by two-probe scanning tunneling microscopy with Ohmic contact

  • PC Department Online Seminar
  • Date: Jan 10, 2022
  • Time: 04:00 PM (Local Time Germany)
  • Speaker: Dr. Jo Onoda
  • University of Alberta, Canada
Relentless downscaling of conventional electronic devices demands continuous improvement in characterization of microscopic surface electronic properties. Moreover, in the pursuit of more exploratory device concepts such as atomic-scale logic gates [1] and memories [2] composed of dangling bonds on hydrogen-terminated Si surfaces there is great need for characterization of extremely small one- and two-dimensional structures. [more]

Electron microscopy in heterogeneous catalysis

CatLab Lectures Modern Methods in Heterogeneous Catalysis Research
Modern Methods in Heterogeneous Catalysis Research. A series of independent lectures on basic principles and new challenges in catalysis research. The lecture series is aimed at PhD students and scientists who are interested in interfacial phenomena and the design and investigation of functional 3D and 2D materials. [more]

Excitons and Lattice Dynamics in Novel Semiconductor Materials Probed by Optical Spectroscopy

  • Department Online Seminar
  • Date: Dec 13, 2021
  • Time: 03:00 PM (Local Time Germany)
  • Speaker: Dr. Joanne Urban
  • École Normale Supérieure Paris-Saclay
2D layered semiconductors are both a fascinating platform to investigate quantum and dielectric confinement phenomena and versatile candidates for optoelectronic applications. Hybrid 2D layered perovskites combine large exciton binding energies with unique properties related to the dynamics of their soft, polar lattice. [more]

Nanovideography of ultrafast charge carrier dynamics in van der Waals materials

  • PC Department Online Seminar
  • Date: Dec 6, 2021
  • Time: 11:00 AM (Local Time Germany)
  • Speaker: Dr. Markus Huber
  • Universität Regensburg
The terahertz and mid-infrared spectral domain host a multitude of interesting low-energy elementary excitations, such as phonons, plasmons and magnons. Ultrafast optical spectroscopy has provided key insights into the dynamics of these collective excitations. Unfortunately, the spatial resolution of such (far-field) studies is intrinsically limited to the scale of the probing wavelength by diffraction. Thus, the optical response cannot resolve individual nano-objects, confined polariton waves, or local surface effects. [more]

Photoelectron spectroscopy in catalysis research

CatLab Lectures Modern Methods in Heterogeneous Catalysis Research
Modern Methods in Heterogeneous Catalysis Research. A series of independent lectures on basic principles and new challenges in catalysis research. The lecture series is aimed at PhD students and scientists who are interested in interfacial phenomena and the design and investigation of functional 3D and 2D materials. [more]

Visualizing Electron Localization and Minibands in WS2/WSe2 Moiré Superlattices

  • PC Department Online Seminar
  • Date: Nov 29, 2021
  • Time: 09:00 AM (Local Time Germany)
  • Speaker: Conrad Stansbury
  • University of California, Berkeley
  • Host: Tommaso Pincelli
The ability to engineer flattened electronic bands by controlling interlayer effects in moiré superlattices of two-dimensional materials has opened the door for material physicists to understand and control correlated electron phenomena in an unprecedentedly broad class of materials. Despite wide-ranging transport and optical signatures of correlated phases, a holistic understanding of how exotic quantum phases emerge remains elusive. [more]

Vibrational spectroscopies in heterogeneous catalysis

CatLab Lectures Modern Methods in Heterogeneous Catalysis Research
Modern Methods in Heterogeneous Catalysis Research. A series of independent lectures on basic principles and new challenges in catalysis research. The lecture series is aimed at PhD students and scientists who are interested in interfacial phenomena and the design and investigation of functional 3D and 2D materials. [more]
Recently, the more than 20-year-old data archive of the AC department was replaced by a new version. In the seminar, this new release will be briefly presented and users will have the opportunity to ask questions and make suggestions. This local data infrastructure will also be used by cooperation partners in the ISC department, at the BasCat laboratory of the TU Berlin and at HZB. Colleagues who do not use this archive are welcome to take a look at this type of data archiving, which is especially tailored to research data generated in the study of functional materials. [more]

Multilayer supramolecular architectures at device interfaces: Prospects for electron and phonon transport

  • PC Department Online Seminar
  • Date: Nov 22, 2021
  • Time: 11:00 AM (Local Time Germany)
  • Speaker: Prof. Carlos-Andres Palma
  • Institute of Physics Chinese Academy of Sciences & Humboldt-Universität zu Berlin
  • Host: Akitoshi Shiotari
Manufacturing atomically-precise functional nanoarchitectures with tailored physics at well-defined device interfaces is a frontier in bottom-up nanomaterial [1,2] and condensed matter design [3]. A long-standing challenge in the field is the integration of functional elements in proof-of-concept devices. One strategy to alleviate the cumbersome device integration of single-layered molecular systems, is to achieve increasing control over vertical supramolecular heterojunctions and multilayers, so as to transition from ‘on-surface’, to ‘out-of-surface’ surface science protocols. [more]

Thermal analysis

CatLab Lectures Modern Methods in Heterogeneous Catalysis Research
Modern Methods in Heterogeneous Catalysis Research. A series of independent lectures on basic principles and new challenges in catalysis research. The lecture series is aimed at PhD students and scientists who are interested in interfacial phenomena and the design and investigation of functional 3D and 2D materials. [more]

Atomically-resolved interlayer charge ordering and its interplay with superconductivity in YBa2Cu3O6.81

  • Joint Seminar
  • Date: Nov 8, 2021
  • Time: 09:00 AM (Local Time Germany)
  • Speaker: Prof. Ya-Ping Chiu
  • Department of Physics, National Taiwan University, Taipei, Taiwan
  • Host: Takashi Kumagai
Joint seminar of Fritz Haber Institute and Institute for Molecular Science, Japan. Charge order (CO) has been recognized as one of the most important competing order in superconductive cuprates. In YBa2Cu3O6+x (YBCO), CO could only be investigated by x-ray diffraction in under-doped YBCO with low critical temperatures (TC), but not in highly-doped YBCO with high TC suitable for device applications, due to the competing superconductive phase. Therefore, the most fundamental physical mechanisms governing CO, for example, the role of so-called charge reservoir (Cu-O chain) layers in CO and the spatial interplay of CO and SC, in highly-doped YBCO are still unclear. [more]

Analysis of the bulk and defect structure of catalysts

CatLab Lectures Modern Methods in Heterogeneous Catalysis Research
Modern Methods in Heterogeneous Catalysis Research. A series of independent lectures on basic principles and new challenges in catalysis research. The lecture series is aimed at PhD students and scientists who are interested in interfacial phenomena and the design and investigation of functional 3D and 2D materials. [more]
In this seminar we want to present the possibilities of automatic data acquisition, data processing and storage in an archive.We will discuss current experiments with proprietary devices as well as systems with generic devices (MFCs, Temp-Controller).We follow the idea of the FAIR principle and want to create the conditions for the application of Big Data analysis and data mining methods.For this, reliable, reproducible data sets with high diversity are needed. To generate such data, handbooks are used in which the characterization of catalysts and the determination of kinetic data are precisely prescribed. These handbooks should specify the minimum data set that should be generated for each catalyst and how the measurements should be performed.To achieve these goals, various software and hardware components are needed. Here are some examples that will be presented in this talk: [more]

Synthesis of heterogeneous catalysts

CatLab Lectures Modern Methods in Heterogeneous Catalysis Research
Modern Methods in Heterogeneous Catalysis Research. A series of independent lectures on basic principles and new challenges in catalysis research. The lecture series is aimed at PhD students and scientists who are interested in interfacial phenomena and the design and investigation of functional 3D and 2D materials. [more]

Concepts in heterogeneous catalysis

CatLab Lectures Modern Methods in Heterogeneous Catalysis Research
Modern Methods in Heterogeneous Catalysis Research. A series of independent lectures on basic principles and new challenges in catalysis research. The lecture series is aimed at PhD students and scientists who are interested in interfacial phenomena and the design and investigation of functional 3D and 2D materials. [more]

The discovery and applications of topological quasiparticles by ultrafast microscopy

  • PC Department Online Seminar
  • Date: Oct 19, 2021
  • Time: 11:00 AM (Local Time Germany)
  • Speaker: Prof. Hrvoje Petek
  • University of Pittsburgh
  • Host: Martin Wolf
Surface plasmon polaritons (SPP) are composite electromagnetic field-charge density wave collective modes that propagate at metal/dielectric interfaces at the local speed of light. The circulation of their fields from transverse to longitudinal causes a transverse spin angular momentum (SAM) locking known as quantum spin-Hall effect, which embodies the property of evanescent waves, such as SPPs, that changing the sign of the photon momentum direction changes the sign of its spin. In other words, the oppositely propagating SPP waves possess the opposite spin. SPP fields can also carry optical angular momentum (OAM), which can focus them into plasmonic vortices. [more]

FHI Library Workshop: Information Resources & Open Access

This workshop will introduce available options for making your research outputs open access. Discover which publishing fees are paid centrally or by the FHI library and get practical tips on how to adopt open access practices in your research area. Furthermore, you will get an overview of useful search tools. The workshop will be held in the FHI library (building A) and lasts about 45 minutes. The number of participants is limited to five. Please register and inform us about your focus of interest.

Ultrafast Structural Dynamics of Elementary Water-Mediated Proton Transfer Processes

Proton transport between acids and bases in aqueous solution involves the exchange of protons, rearrangements of hydrogen bonds, and the changes in electron charge distributions of all molecules involved. Progress in the development of ultrafast structurally resolving techniques have enabled to follow in real-time the elementary individual steps in proton transfer that occur on femto- to picosecond time scales. Ultrafast probing in the mid-infrared has provided a wealth of information on hydrogen bond dynamics and proton transfer time scales. Recent progress in soft X-ray spectroscopy of solution phase acids and bases using novel flatjet technology has now made possible to locally probe electronic structure. I will showcase this with examples on proton hydration, and photoacid molecular systems, and indicate how further advances in ultrafast soft X-ray spectroscopy of solution phase proton transfer may be made. [more]

Vibrational exciton and polaron nano-imaging: a molecular ruler to image structure, coupling, and disorder in functional molecular materials

Properties and functions of molecular materials often emerge from intermolecular interactions and associated nanoscale structure and morphology. However, defects and disorder give rise to confinement and many-body localization of the associated wavefunction, disturbing the performance of, e.g., molecular electronic or photonic materials. Conventional microscopy and even nanoscopy lack spatio-spectral sensitivity to the low-energy and molecular length scales of intermolecular interactions, carrier-phonon coupling, and polaron formation, thus leaving a missing link between material structure and observed heterogeneity in the electronic or photonic response.We address these outstanding problems in several novel combinations of spatio-spectral and spatio-temporal infrared nano-imaging. [more]

FHI Library Online Workshop: Databases

Our interactive online workshop will help you to select and apply the most appropriate resources and tools for your research. Learn more on how to quickly find and analyze relevant scientific literature. The two databases Web of Science and SciFinder will be presented and discussed in detail. More details on how to join the workshop will be announced by e-mail or contact the library team.

FHI Library Online Workshop: Information Resources & Open Access

This interactive online workshop will introduce available options for making your research outputs open access. Discover which publishing fees are paid centrally or by the FHI library and get practical tips on how to adopt open access practices in your research area. Furthermore, you will get an overview of useful search tools. More details on how to join the workshop will be announced by e-mail or contact the library team.

Controlling the uncontrollable: Quantum control of open systems

Quantum control addresses the issue of driving a system to a desired objective. Manipulation of quantum systems is achieved by coherent control which relies on constructive and destructive interference of the quantum amplitudes, i.e., quantum coherence. The key ingredient, coherence, is extremely sensitive to any external perturbation. In reality all quantum systems are open, thus, are subject to environmental effects. The interaction with the environment degrades the required agent, coherence, leading to a detrimental effect on coherent control. Quantum control of an open system is therefore a challenge. For this study we employ a thermodynamically consistent master equation. In this framework, the open system dynamics depend on the control protocol due to the dressing of the system by the drive. This interrelation serves as the key element for control. The influence of the external drive is incorporated within the dynamical equation, enabling an indirect control of the dissipation. The control paradigm is displayed by analyzing entropy changing state to state transformations, heating and cooling N-levels systems, accelerating the approach to equilibrium. Following, we study the generation of quantum non-unitary maps via coherent control. These include both reset maps with complete memory loss. The other extreme where the control is optimized to minimize the dissipation is demonstrated by a single and two qubit unitary maps. [more]

Ultrafast Infrared Spectroscopy at the Nanoscale

  • Joint Online Seminar
  • Date: Sep 6, 2021
  • Time: 10:00 AM (Local Time Germany)
  • Speaker: Jun Nishida
  • Center for Mesoscopic Sciences, Institute for Molecular Science, Japan
  • Host: Fritz Haber Institute
Emerging functional materials exhibit “liquid-like” dynamics associated with their soft lattice structures, often with spatial heterogeneity at length scales ranging from tens to hundreds of nanometers. Yet, tools to characterize such dynamical disorder have not been established. While nonlinear infrared spectroscopy has elucidated dynamics of liquids and solutions over the past decades, the limited sensitivity and the fundamental diffraction limit have hampered its applications to material systems at the nanoscale. [more]

FHI Library Online Workshop: Information Resources & Open Access

This interactive online workshop will introduce available options for making your research outputs open access. Discover which publishing fees are paid centrally or by the FHI library and get practical tips on how to adopt open access practices in your research area. Furthermore, you will get an overview of useful search tools. More details on how to join the workshop will be announced by e-mail or contact the library team.

FHI Library Online Workshop: Databases

Our interactive online workshop will help you to select and apply the most appropriate resources and tools for your research. Learn more on how to quickly find and analyze relevant scientific literature. The two databases Web of Science and SciFinder will be presented and discussed in detail. More details on how to join the workshop will be announced by e-mail or contact the library team.

How to publish your science: A guide to writing your first re-search article, and every article after that

Scientific writing is an integral part of any researcher’s career, aimed at communicating original research for peer review. Well written articles backed by citable scientific data help expedite peer collaboration and advancements in any field. [more]

Engineering pi-conjugated nanomaterials on surfaces

Joint seminar of Fritz Haber Institute and Institute for Molecular Science, Japan. The design of pi-conjugated nanomaterials is at the vanguard of science and technology taking into account the interest in optoelectronics,nanomagnetism, quantum information and non-trivial quantum phases of matter.In this talk I will revise our efforts in the last couple of years to engineer on surfaces pi-conjugated polymers and networks that could expressnon-trivial topological quantum classes. [more]

Thermodynamic properties by on-the-fly machine-learned interatomic potentials: thermal transport and phase transitions

Computational Understanding of Electrochemical Energy Storage Materials

The complete electrification of the transport sector will require batteries that can be made from abundant chemical species and exhibit significantly greater energy density than current Li-ion batteries. [more]

FHI Library Online Workshop: Information Resources & Open Access

This interactive online workshop will introduce available options for making your research outputs open access. Discover which publishing fees are paid centrally or by the FHI library and get practical tips on how to adopt open access practices in your research area. Furthermore, you will get an overview of useful search tools. More details on how to join the workshop will be announced by e-mail or contact the library team.
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