German Science and Humanities Council recommends research building for materials sciences

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A research building together with a modern transmission electron microscope will be established on the Lahnberge campus of Philipps-University Marburg

Dr. Andreas Beyer, a researcher in SFB 1083, operates a Transmission Electron Microscope, which provides important insights in the development of new materials.

On the Lahnberge Campus, a new research building for a transmission electron microscope for the investigation of novel materials will be established. The German Science and Humanities Council gave its recommendation for the project, which is called ATEMMA (Advanced Transmission Electron Microscopy, Marburg). ATEMMA comprises a volume of 10 Mio €. This is divided into 4 Mio € for the building itself as well as 6 Mio € for the new (S)TEM.

ATEMMA strengthens the focus on material sciences and especially on interfaces at the Philipps-University Marburg and paves the way for high-quality research, e.g., on new materials used for communication and energy technologies, as these represent extremely important topics in our today’s society. The new research lab combines structural characterization with the development of new methods. This combination will boost the research on novel materials also with respect to device applications.

ATEMMA will be used jointly by different groups from physics, chemistry and material sciences distributed over the Philipps-University Marburg as well as Justus-Liebig-University Giessen and the Forschungscampus Mittelhessen. Several of the groups are also part of the SFB 1083, highlighting the importance of interface-related research for ATEMMA.

For further information, please see the press release by the Philipps-Universität Marburg (in German).

Update (12.07.2022): ATEMMA was now officially granted and is scheduled to go into operation in 2026. Again, please see the press release by the Philipps-Universität Marburg for further infromation (in German).

Contact

Prof. Dr. Kerstin Volz
Department of Physics and Materials Science Center
Philipps-Universität Marburg
Tel.: 06421 28-22297
EMAIL

Dr. Gerson Mette (B5) completed his habilitation at the Philipps-University Marburg

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We congratulate Dr. Gerson Mette, former PI of SFB project B5, on completing his habilitation in experimental physics at the Philipps-University Marburg.

Dr. Gerson Mette studied physics at the Philipps-University Marburg and finished his PhD in the group of Prof. Höfer in 2012. After working as a postdoc at the University of Zurich for two years, he went back to Marburg and became a research associate in 2015 while simultaneously joining the SFB 1083 as a young researcher and co-PI of project B5.

With his broad background in surface science and laser spectroscopy, he has set up new SHG imaging microscopy for pump-probe experiments of van der Waals heterostructures and explored the dynamics of charge-transfer processes across interfaces of 2D materials in well-defined environments. Furthermore, he explored the influence of electronic interface states on the ultrafast charge-transfer at buried GaP/Si interfaces.

In February 2022 he gave his habilitation talk on “How big is the proton? The proton radius puzzle” and completed his habilitation in experimental physics. The members of the SFB thank Dr. Mette for his work and commitment for the SFB 1083 and wish him all the best on his future career path.

Terahertz Fingerprint of Monolayer Wigner Crystals – Publication by B9 (Malic) in Nano Letters

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The Ultrafast Quantum Dynamics group of Ermin Malic (Project B9) together with Rudolf Bratschitsch from the University of Münster revealed unexpected transport behavior of excitons in ultrathin semiconductors

Sketch of the 2D Wigner crystal with a honeycomb lattice and alternating spin polarization. The colored curves underneath the particles illustrate their wave functions. Reprinted with permission from Brem et al. Copyright 2022 American Chemical Society.

Wigner crystals are solid, crystalline phases of electrons, formed at low temperatures in order to minimize their repulsive energy. This formation is one of the most intriguing quantum phase transitions and their experimental realization remains challenging since their theoretical prediction. However, the strong Coulomb interaction in monolayer semiconductors represents a unique opportunity for the realization of Wigner crystals without external magnetic fields.

In this work, the group of Ermin Malic predicts that the formation of monolayer Wigner crystals can be detected by their terahertz response spectrum, which exhibits a characteristic sequence of internal optical transitions. The density matrix formalism was used to derive the internal quantum structure and the optical conductivity of the Wigner crystal and to microscopically analyze the multipeak shape of the obtained terahertz spectrum. Moreover, a characteristic shift of the peak position as a function of charge density for different atomically thin materials was predicted and showed how the results can be generalized to an arbitrary two-dimensional system.

The results will guide future experiments toward the detection of Wigner crystallization and help to study the interaction dynamics in pure and generalized Wigner crystals in twisted bilayers.

Publication

S. Brem, E. Malic
Terahertz Fingerprint of Monolayer Wigner Crystals
Nano Lett. (2022) DOI:10.1021/acs.nanolett.1c04620

Contact

Prof. Dr. Ermin Malic
Philipps-Universität Marburg
SFB 1083 project B9
Tel.: 06421 28-22640
EMAIL