Together with the theory groups of Ermin Malic (Chalmers University of Technology, Sweden) and Andreas Knorr (TU Berlin) we reveal a new type of coupling (Dexter-like) between states of equal spin in the K and K' valleys in a 2D semiconductor. It results in an inverted valley polarization and broadening of excitonic resonances.
Inverted valley polarization in optically excited transition metal dichalcogenides, G. Berghäuser, I. Bernal-Villamil, R. Schmidt, R. Schneider, I. Niehues, P. Erhart, S. Michaelis de Vasconcellos, R. Bratschitsch, A. Knorr, and E. Malic, Nature Communications 9, 971 (2018)
Exciton broadening and band renormalization due to Dexter-like intervalley coupling, I. Bernal-Villamil, G. Berghäuser, M. Selig, I. Niehues, R. Schmidt, R. Schneider, P. Tonndorf, P. Erhart, S. Michaelis de Vasconcellos, R. Bratschitsch, A. Knorr, and E. Malic, 2D Materials 5, 025011 (2018)
Together with the groups of Michael Rohlfing (Münster), Ermin Malic (Chalmers University of Technology, Sweden), Andreas Knorr (TU Berlin), Tilmann Kuhn (Münster), and Andres Castellanos-Gomez (Madrid) we show that the excitonic line width in atomically thin semiconductors can be controlled by mechanical strain.
Strain control of exciton-phonon coupling in atomically thin semiconductors, I. Niehues, R. Schmidt, M. Drüppel, P. Marauhn, D. Christiansen, M. Selig, G. Berghäuser, D. Wigger, R. Schneider, L. Braasch, R. Koch, A. Castellanos-Gomez, T. Kuhn, A. Knorr, E. Malic, M. Rohlfing, S. Michaelis de Vasconcellos, and R. Bratschitsch, Nano Letters, DOI: 10.1021/acs.nanolett.7b04868 (2018)
Our PhD students Robert Schneider, Johann Preuß, and Iris Niehues (from left to right on photo) have attended the Alfried Krupp prize ceremony at the Villa Hügel in Essen. They met with previous awardees to discuss career paths in science and listened to the presentations of Immanuel Bloch (MPQ Munich) and this year's winner Alexander Szameit (University of Rostock).
We are co-organizing the 5th International Workshop on the Optical Properties of Nanostructures (OPON 2018) in Münster, 14-16 February 2018. The abstract submission deadline is 15 December 2017.
Together with the theory groups of Andreas Knorr (TU Berlin) and Ermin Malic (Chalmers University of Technology, Sweden) we explain how exciton-phonon scattering governs the excitonic line shape of atomically thin semiconductors.
Phonon sidebands in monolayer transition metal dichalcogenides, D. Christiansen, M. Selig, G. Berghäuser, R. Schmidt, I. Niehues, R. Schneider, A. Arora, S. Michaelis de Vasconcellos, R. Bratschitsch, E. Malic, and A. Knorr Phys. Rev. Lett. 119, 187402 (2017)
We participated in the "Highlights der Physik" science fair (18-23 September 2017) in Münster with our booth about carbon structures (diamond, graphite, carbon nanotubes, fullerenes, and graphene).
Together with the theory group of Michael Rohlfing (University of Münster) and Marek Potemski (High magnetic field lab in Grenoble, France) we report on interlayer excitons in a layered bulk semiconductor (MoTe2).
Interlayer excitons in a bulk van der Waals semiconductor, A. Arora, M. Drüppel, R. Schmidt, T. Deilmann, R. Schneider, M. R. Molas, P. Marauhn, S. Michaelis de Vasconcellos, M. Potemski, M. Rohlfing, and R. Bratschitsch Nature Communications 8, 639 (2017)
Together with the groups of Wolfram Pernice (University of Münster) and Alexander Tartakovskii (University of Sheffield, UK) we have coupled a single-photon emitter in the layered semiconductor GaSe into a dielectric waveguide on a photonic chip.
On-chip waveguide coupling of a layered semiconductor single-photon source, P. Tonndorf, O. Del Pozo Zamudio, N. Gruhler, J. Kern, R. Schmidt, A. I. Dmitriev, A. P. Bakhtinov, A. I. Tartakovskii, W. HP Pernice, S. Michaelis de Vasconcellos, and R. Bratschitsch Nano Lett. 17, 5446 (2017)