@article{40444, author = {{von Bardeleben, H. J. and Rauls, E. and Gerstmann, Uwe}}, issn = {{2469-9950}}, journal = {{Physical Review B}}, number = {{18}}, publisher = {{American Physical Society (APS)}}, title = {{{Carbon vacancy-related centers in 3C-silicon carbide: Negative-U properties and structural transformation}}}, doi = {{10.1103/physrevb.101.184108}}, volume = {{101}}, year = {{2020}}, } @article{17070, abstract = {{

EPR spectroscopy reveals the universality class and dynamic effects of the [NH4][Zn(HCOO)3] hybrid formate framework.

}}, author = {{Navickas, Marius and Giriūnas, Laisvydas and Kalendra, Vidmantas and Biktagirov, Timur and Gerstmann, Uwe and Schmidt, Wolf Gero and Mączka, Mirosław and Pöppl, Andreas and Banys, Jūras and Šimėnas, Mantas}}, issn = {{1463-9076}}, journal = {{Physical Chemistry Chemical Physics}}, pages = {{8513--8521}}, title = {{{Electron paramagnetic resonance study of ferroelectric phase transition and dynamic effects in a Mn2+ doped [NH4][Zn(HCOO)3] hybrid formate framework}}}, doi = {{10.1039/d0cp01612h}}, volume = {{22}}, year = {{2020}}, } @article{29745, author = {{Biktagirov, Timur and Gerstmann, Uwe}}, issn = {{2643-1564}}, journal = {{Physical Review Research}}, keywords = {{General Engineering}}, number = {{2}}, publisher = {{American Physical Society (APS)}}, title = {{{Spin-orbit driven electrical manipulation of the zero-field splitting in high-spin centers in solids}}}, doi = {{10.1103/physrevresearch.2.023071}}, volume = {{2}}, year = {{2020}}, } @article{19189, abstract = {{Density-functional theory calculations of (TiO2)n clusters (n = 1–5) in the gas phase and adsorbed on pristine graphene as well as graphene quantum dots are presented. The cluster adsorption is found to be dominated by van der Waals forces. The electronic structure and in particular the excitation energies of the bare clusters and the TiO2/graphene composites are found to vary largely in dependence on the size of the respective constituents. This holds in particular for the energy and the spatial localization of the highest occupied and lowest unoccupied molecular orbitals. In addition to a substantial gap narrowing, a pronounced separation of photoexcited electrons and holes is predicted in some instances. This is expected to prolong the lifetime of photoexcited carriers. Altogether, TiO2/graphene composites are predicted to be promising photocatalysts with improved electronic and photocatalytic properties compared to bulk TiO2.}}, author = {{Badalov, Sabuhi and Wilhelm, René and Schmidt, Wolf Gero}}, issn = {{0192-8651}}, journal = {{Journal of Computational Chemistry}}, pages = {{1921--1930}}, publisher = {{Willey}}, title = {{{Photocatalytic properties of graphene‐supported titania clusters from density‐functional theory}}}, doi = {{10.1002/jcc.26363}}, year = {{2020}}, } @article{20773, abstract = {{AbstractSemiconductor quantum dots are excellent candidates for ultrafast coherent manipulation of qubits by laser pulses on picosecond timescales or even faster. In inhomogeneous ensembles a macroscopic optical polarization decays rapidly due to dephasing, which, however, is reversible in photon echoes carrying complete information about the coherent ensemble dynamics. Control of the echo emission time is mandatory for applications. Here, we propose a concept to reach this goal. In a two-pulse photon echo sequence, we apply an additional resonant control pulse with multiple of 2π area. Depending on its arrival time, the control slows down dephasing or rephasing of the exciton ensemble during its action. We demonstrate for self-assembled (In,Ga)As quantum dots that the photon echo emission time can be retarded or advanced by up to 5 ps relative to its nominal appearance time without control. This versatile protocol may be used to obtain significantly longer temporal shifts for suitably tailored control pulses.}}, author = {{Kosarev, Alexander N. and Rose, Hendrik and Poltavtsev, Sergey V. and Reichelt, Matthias and Schneider, Christian and Kamp, Martin and Höfling, Sven and Bayer, Manfred and Meier, Torsten and Akimov, Ilya A.}}, issn = {{2399-3650}}, journal = {{Communications Physics}}, number = {{1}}, title = {{{Accurate photon echo timing by optical freezing of exciton dephasing and rephasing in quantum dots}}}, doi = {{10.1038/s42005-020-00491-2}}, volume = {{3}}, year = {{2020}}, } @article{43747, abstract = {{Vortices are topological objects representing the circular motion of a fluid. With their additional degree of freedom, the vorticity, they have been widely investigated in many physical systems and different materials for fundamental interest and for applications in data storage and information processing. Vortices have also been observed in non-equilibrium exciton-polariton condensates in planar semiconductor microcavities. There they appear spontaneously or can be created and pinned in space using ring-shaped optical excitation profiles. However, using the vortex state for information processing not only requires creation of a vortex but also efficient control over the vortex after its creation. Here we demonstrate a simple approach to control and switch a localized polariton vortex between opposite states. In our scheme, both the optical control of vorticity and its detection through the orbital angular momentum of the emitted light are implemented in a robust and practical manner.}}, author = {{Meier, Torsten and Ma, Xuekai and Berger, Bernd and Aßmann, Marc and Driben, Rodislav and Schneider, Christian and Höfling, Sven and Schumacher, Stefan}}, journal = {{Nature communications}}, number = {{1}}, pages = {{897}}, publisher = {{Nature Publishing Group UK}}, title = {{{Realization of all-optical vortex switching in exciton-polariton condensates}}}, doi = {{10.1038/s41467-020-14702-5}}, volume = {{11}}, year = {{2020}}, } @inproceedings{20770, author = {{Hannes, Wolf-Rüdiger and Meier, Torsten}}, booktitle = {{Ultrafast Phenomena and Nanophotonics XXIV}}, editor = {{Betz, Markus and Elezzabi, Abdulhakem Y.}}, isbn = {{9781510633193}}, pages = {{112780S}}, title = {{{k.p-based multiband simulations of non-degenerate two-photon absorption in bulk GaAs}}}, doi = {{10.1117/12.2545924}}, volume = {{11278}}, year = {{2020}}, } @article{20563, author = {{Hannes, W.-R. and Trautmann, Alexander and Stein, M. and Schäfer, F. and Koch, M. and Meier, Torsten}}, journal = {{Physical Review B}}, number = {{7}}, pages = {{075203}}, publisher = {{American Physical Society}}, title = {{{Strongly nonresonant four-wave mixing in semiconductors}}}, doi = {{10.1103/PhysRevB.101.075203}}, volume = {{101}}, year = {{2020}}, } @article{20772, author = {{Song, Xiaohong and Yang, Shidong and Zuo, Ruixin and Meier, Torsten and Yang, Weifeng}}, issn = {{2469-9926}}, journal = {{Physical Review A}}, title = {{{Enhanced high-order harmonic generation in semiconductors by excitation with multicolor pulses}}}, doi = {{10.1103/physreva.101.033410}}, volume = {{101}}, year = {{2020}}, } @article{20682, author = {{Bocchini, Adriana and Eigner, Christof and Silberhorn, Christine and Schmidt, Wolf Gero and Gerstmann, Uwe}}, journal = {{Phys. Rev. Materials}}, pages = {{124402}}, publisher = {{American Physical Society}}, title = {{{Understanding gray track formation in KTP: Ti^3+ centers studied from first principles}}}, doi = {{10.1103/PhysRevMaterials.4.124402}}, volume = {{4}}, year = {{2020}}, }