New Emmy Noether Group
Dr Sebastian Maehrlein, head of the "THz Structural Dynamics" research group in the Department of Physical Chemistry at the Fritz Haber Institute, has received a top-class grant: Starting in October, the German Research Foundation (DFG) will provide him with a budget of 1.6 million euros for an independent Emmy Noether junior research group. The research focus is on controlling the angular momentum of atomic lattices for the ultrafast control of material properties.
“Leading an independent DFG-funded Emmy Noether group complimented with the excellent Max Planck infrastructure can only be the dream for a young scientist working in fundamental research. This broad support enables my group to study the fundamental property of lattice angular momentum, to date a vastly neglected aspect of contemporary solid state physics.” explains Dr Maehrlein, who currently leads a research group at the Department of Physical Chemistry at Fritz Haber Institute (FHI) in Berlin. He is excited about the 6-year Emmy Noether funding period, also to extend his teaching experience (currently lecturing at Technical University Berlin). “Working with ambitious PhD students and curious undergrads has always been an important driving force for me”, emphasizes the physicist.
Sebastian Maehrlein’s research generally aims to use collective motions of the atomic lattice as an active control to steer material properties on ultrafast time scales. Already during his PhD, he demonstrated that coherent lattice vibrations (phonons) can be employed to change electron spins and thus the magnetic order of solids. Now, if phonons not only transfer energy and linear momentum, but also a precise amount of angular momentum, this will provide a novel controllable coupling channel. Such results would represent the ultrafast reversal of the famous experiments by Einstein and de Haas in 1915. Moreover, the research team aims to control the charge carriers’ spin properties via circular polarized phonons (lattice ions on a circular trajectory) in atomically thin semiconductors. To enable this ambitious research direction, Dr. Maehrlein and his team will develop methods for tailoring polarization states of intense few-cycle laser pulses in the far-infrared Terahertz (THz) and multi-THz spectral region. “To put it simply: with this we hope to force lattice ions into clockwise or counter-clockwise corkscrew or circular motions”, explains Sebastian Maehrlein.
Already during his master in physics (German “Diplom”) at the University of Konstanz, Sebastian F. Maehrlein employed highly intense THz radiation and investigated its interaction with fundamental excitations in solids. After his following interdisciplinary innovation studies at Hasso Plattner Institute in Potsdam, he started his PhD in physics at Free University Berlin and Fritz Haber Institute; graduating in 2016. In the following, he moved to Columbia University in New York for his postdoctoral research. In 2020, Dr. Maehrlein returned to Germany to start his own research group at the Department of Physical Chemistry at FHI. The Emmy Noether Program of the German Research Foundation (DFG) generally aims to give highly qualified researchers the opportunity to satisfy the prerequisites for appointment as a university professor by leading an independent junior research group and performing relevant teaching duties.