Host: Department of Molecular Physics

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

Quantum sensors on Earth and in space

The development of quantum sensors has been one of the most important – and arguably currently most advanced – pillars of the ongoing efforts toutilize quantum technologies for practical applications. [more]

Quantum Science and Technologies using Ultracold Molecules

Ultracold molecules have a wide range of applications in quantum science and technologies spanning from fundamental physics to quantum computing and quantum chemistry, and this has sparked great interest in laser cooling of molecules. [more]

Low energy electron emission from charge exchange of slow highly charged ions with solid surfaces

The interaction of slow ions with condensed matter leads to the emission of electrons with energies typically well below 20eV. [more]

Extracting Chemistry From Core-Level Spectroscopies: Combining Theory And Experiment

The goal of X-Ray Photoelectron Spectroscopy, XPS, and X-Ray Adsorption Near Edge Spectroscopy, XANES, is to obtain information about the chemical interactions and bonding in the compound studied. [more]

Mass spectrometry in electrocatalysis research

Understanding reaction mechanisms is the key to developing new chemical reactions. [more]

New Experimental Platforms for Molecular Polaritonics

Polaritons are hybrid light-matter states with unusual properties that arise from strong interactions between a molecular ensemble and the confined electromagnetic field of an optical cavity. [more]

Thermochemistry: It’s not boring anymore!!!

One of the important areas of application for modern high-accuracy quantum chemistry is in the calculation of molecular energetics. [more]

Homogeneous Bose gases driven far from thermal equilibrium

Far-from-equilibrium systems are ubiquitous in nature, such as in glasses, active matter, and turbulence, but are still poorly understood when compared to the unifying description of thermodynamics for systems in thermal equilibrium. [more]

Tabletop transient NEXAFS spectroscopy with a laser-produced plasma source

Laboratory-based laser-produced plasma (lpp) soft X-ray sources achieve high brightness and stability in the EUV and XUV range. With emission energies beyond 1.6 keV and stable operating times in the range of hours, they already offer numerous experimental possibilities that are independent and supplemental to investigations at large scale facilities. [more]

Brain States and the Mystery of Cognition: Using magnetic resonance imaging (MRI) to map the brain

Patterns of neural activity distributed across the brain are termed “brain states”. [more]

Insights into Scientific Publishing

Publishing your work in an influential journal begins with good research, but there is much more to it. This interactive talk aims to demystify the editorial process from the perspective of an editor at a Nature Portfolio journal. [more]

Quantum mixtures of atoms and ions: road to ultracold

Ultracold atoms and trapped ions are among the most formidable sources of coherent matter available in a laboratory. In a hybrid quantum system of atoms and ions, ultracold atoms and trapped ions are combined in a single experimental apparatus, thus realizing an innovative platform to experimentally investigate open problems of quantum physics from a new standpoint. [more]

Sommerfest | Summer Party

Die Abteilung Molekülphysik (MP) freut sich, Euch alle zum diesjährigen FHI-Sommerfest einzuladen! | The Molecular Physics (MP) department is delighted to invite you all to this years summer party! [more]

About thermionic electron emission and associative ionization

[more]

Big data, small data, complex data, more data, metadata − Tackling current and future challenges of scientific IT

Science faces the challenge of ever-increasing and more complex data that push existing evaluation methods to their limits. Additional requirements such as reproducibility, data security, consistency, transferability, and reusability cause significant effort and are hardly met by traditional manual workflows. [more]

Dynamics of CO2 activation by transition metal ions - The importance of intersystem crossing

Understanding chemistry at the level of a reactive collision, that is how atoms rearrange during the reactive event, is a fundamental question in chemistry as well as in physics. [more]

Systems Metrology at ZEISS Semiconductor Manufacturing Technology

Precise optics produced by ZEISS Semiconductor Manufacturing Technology (SMT) are a centerpiece of ASML photolithography machines. These tools are indispensable for digitalization: over 80% of today’s microchips are manufactured on ASML wafer steppers and scanners. [more]

Missing Ions in Laboratory and Space

Molecular ions play a vital role in space because they are readily formed by the ubiquitous cosmic ray ionisation and often undergo rapid chemical reactions even at the low temperatures of the interstellar medium. [more]

Angular momentum of small molecules: quasiparticles and topology

I will present our recent findings on small molecules kicked by laser pulses. First, I will describe a technique that allows to probe highly excited molecular states in the presence of an environment, such as superfluid 4He, and a corresponding theory based on angulon quasiparticles that is capable of describing such states, in good agreement with experiment. [more]

Hydrogen/Deuterium 1S-3S spectroscopy and beyond

In this talk, I would like to present our latest result on the 1S-3S two-photon continuous wave spectroscopy of Deuterium atoms. [more]

Record Stability and Accuracy in a Strontium Optical Clock

Atomic clocks have revolutionized precision measurement. Each advancement in timekeeping, from pendulum clocks to quartz oscillators, from microwave atomic clocks to optical atomic clocks, opens the door to new areas of physics. [more]

An introduction to resonant nonlinear optical frequency conversion

Direct single-mode cw laser sources cover a broad wavelength interval for an almost unimaginable range of applications. [more]

Ionization-induced dynamics in water and aqueous solutions uncovered via ultrafast time-resolved x-ray absorption spectroscopy and theoretical modeling

Our understanding of the immediate response of matter to ionization is crucial for many fields. [more]

Para-ortho H2 conversion by collisions with O2 and NO

It has been known since 1927 that two modifications of hydrogen exist: para-H2 and ortho-H2. Pure para-H2 can be prepared by leading a 1:3 para:ortho mixture of “normal” H2 over a catalyst at low temperature. In 1933 Farkas and Sachsse [1] measured the rate coefficient of para-ortho H2 conversion in gas mixtures with the paramagnetic open-shell molecules O2, NO, and NO2. [more]

Helium atom and helium-like ions - where are we today?

The Z-Helium atom is Nature's simplest atomic, 3-body system. [more]

Broken Patterns - Anomalies in the Spectra of Aluminum Monofluoride

Usually, rotational spectra of diatomics can be described by a handful of spectroscopic parameters. [more]

Testing the Standard Model with Molecules

Search for violation of fundamental symmetries provides a unique opportunity for testing the Standard Model. Atomic and molecular experiments offer a low energy and comparatively inexpensive alternative to high energy accelerator research in this field. [more]

The Advanced Research Center for NanoLithography: better chips-making-tools using fundamental physics research.

ARCNL in Amsterdam started in 2014 upon an initiative of ASML. [more]

Laser excitation and spectroscopy of the Thorium-229 nucleus

Among all known isotopes, Thorium-229 has the lowest nuclear excited state, only 8.4 eV above the ground state. [more]

Bridging Native and Intrinsic Structures of Microhydrated Biomolecules by Cryogenic Ion Spectroscopy

Over the years, cryogenic ion spectroscopy has established itself as a powerful technique for studying the structures and properties of biomolecules in the gas phase. [more]

Structural Dynamics of Water, Ice, and Chemical Reactions Revealed by X-ray Experiments at FELs

X-ray science has evolved dramatically with the use of X-ray free electron lasers (XFELs) that can generate ultrashort X-ray pulses with unprecedented brilliance and coherence. [more]

Spectroscopic investigation of proton bonding at sub-kelvin temperatures

The proton bond is a pivotal chemical motif with significant implications across science and technology, yet its quantum chemical description is challenged by nuclear and charge delocalization effects. [more]

Progress in laser cooling the AlF molecule

The aluminium monofluoride molecule (AlF) is a promising candidate for laser cooling and trapping at high densities. [more]

Chirality and the electron spin- A miraculous match

Spin based properties, applications, and devices are commonly related to magnetic effects and to magnetic materials. [more]

Photoelectron and fluorescence spectroscopy of cryogenically cooled ions

Cryogenic ion traps combined with buffer gas cooling provide ideal conditions for preparing molecular ions in their vibrational ground states. [more]

Matter-wave interferometry from electrons to nanoparticles - recent ideas and applications

Modern matter-wave experiments cover a broad mass range from single electrons to molecules consisting of hundreds of atoms. Levitated optomechanics promises to be-come a platform for matter waves of nanoparticles weighing a billion atomic mass units. [more]

Deciphering spectral signatures of proton delocalization in complexes of hydroxide and hydronium ions with water molecules

One class of system where explorations of larger complexes is particularly instructive involves complexes of ions with water molecules. In these systems the cooperative nature of the hydrogen bond that are formed leads to large changes in the strengths of the ion-water interactions as more water molecules are introduced, and this, in turn, has a large effect on the spectroscopy. [more]

Photoelectron Circulardichroism in the Photodetachment of Electrosprayed Anions

Research aiming at the quantification of molecular chirality by chiroptical techniques continues to attract a significant amount of interest in chemistry, physics, biology and pharmacology. [more]

Quantum effects in collisions between rare gas atoms and diatomic molecule ions

Using a combination between both theoretical and experimental techniques, we are able to understand Feshbach resonances occurring in collisions between atoms and molecules, such as for instance Ne-H2+ and Ne-HD+, at a fundamental level. [more]

Hitler's Atomic Bomb

After the discovery of nuclear fission, scientists in several different countries, including National Socialist Germany, brought the potential military applications of fission to the attention of political and military authorities. [more]
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