21 citations · 115 across the 18 of their papers we have counts for
18 papers
Infra-Bayesian Reinforcement Learning Agents Outperform Classical RL For Worst-Case Robustness
Manish Aryal, Faiyaz Azam, Agnivo Banerjee +12
Classical reinforcement learning assumes the agent interacts with a fixed environment whose behavior does not depend on the agent's policy. This assumption breaks down in non-reali…
Impact of the valence band on Rydberg excitons in cuprous oxide quantum wells
Niklas Scheuler, Jörg Main, Patric Rommel +3
The complex valence band structure of bulk cuprous oxide necessitates going beyond the parabolic approximation to precisely estimate exciton binding energies. The same is true for…
Wavefunctions and oscillator strengths of Rydberg excitons in cuprous oxide quantum wells
Leon Kühner, Patric Rommel, Jörg Main +2
We investigate the eigenstates, that is, the wavefunctions of Rydberg excitons in cuprous oxide quantum wells and derive expressions relating them to the oscillator strengths of di…
Quantum defects of Rydberg excitons in cuprous oxide: A semiclassical spherical model
Jan Ertl, Patric Rommel, Jörg Main
Excitons, i.e. the bound states of an electron and a positively charged hole are the solid state analogue of the hydrogen atom. As such they exhibit a Rydberg series, which in cupr…
Bound states in the continuum in cuprous oxide quantum wells
Angelos Aslanidis, Jörg Main, Patric Rommel +2
We propose a realistic semiconductor system containing bound states in the continuum (BICs) which allows for a practical realization. By varying the confinement strength of exciton…
Resonance energies and linewidths of Rydberg excitons in CuO quantum wells
Niklas Scheuler, Patric Rommel, Jörg Main +1
Rydberg excitons are the solid-state analog of Rydberg atoms and can, e.g., for cuprous oxide, easily reach a large size in the region of m for principal quantum numbers up to $…
Classical dynamics and semiclassical analysis of excitons in cuprous oxide
Jan Ertl, Michael Marquardt, Moritz Schumacher +3
Excitons, as bound states of electrons and holes, embody the solid state analogue of the hydrogen atom, whose quantum spectrum is explained within a classical framework by the Bohr…
Gaussian-process-regression-based method for the localization of exceptional points in complex resonance spectra
Patrick Egenlauf, Patric Rommel, Jörg Main
Resonances in open quantum systems depending on at least two controllable parameters can show the phenomenon of exceptional points (EPs), where not only the eigenvalues but also th…
Energy states of Rydberg excitons in finite crystals: From weak to strong confinement
Pavel A. Belov, Florian Morawetz, Sjard Ole Krüger +5
Due to quantum confinement, excitons in finite-sized crystals behave rather differently than in bulk materials. We investigate the dependence of energies of Rydberg excitons on the…
Signatures of exciton orbits in quantum mechanical recurrence spectra of CuO
Jan Ertl, Michael Marquardt, Moritz Schumacher +3
The seminal work by T. Kazimierczuk et al. [Nature 514, 343 (2014)] has shown the existence of highly excited exciton states in a regime, where the correspondence principle is appl…
Interseries dipole transitions from yellow to green excitons in cuprous oxide
Patric Rommel, Jörg Main, Sjard Ole Krüger +1
We study dipole interseries transitions between the yellow and green exciton series in cuprous oxide including the complex valence band structure. To this end, we extend previous s…
Exchange interaction in the yellow exciton series of cuprous oxide
Patric Rommel, Jörg Main, Andreas Farenbruch +2
We experimentally and numerically investigate the exchange interaction of the yellow excitons in cuprous oxide. By varying the material parameters in the numerical calculations, we…
Classical and semiclassical description of Rydberg excitons in cuprous oxide
Jan Ertl, Patric Rommel, Michel Mom +2
Experimental and theoretical investigations of excitons in cuprous oxide have revealed a significant fine-structure splitting of the excitonic Rydberg states caused by a strong imp…
Second Harmonic Generation of cuprous oxide in magnetic fields
Patric Rommel, Jörg Main, Andreas Farenbruch +5
Recently Second Harmonic Generation (SHG) for the yellow exciton series in cuprous oxide has been demonstrated [J. Mund et al., Phys. Rev. B 98, 085203 (2018)]. Assuming perfect $O…
Green exciton series in cuprous oxide
Patric Rommel, Patrik Zielinski, Jörg Main
We numerically investigate the odd parity states of the green exciton series in cuprous oxide. Taking into account the coupling to the yellow series and especially to the yellow co…
Rydberg excitons in electric and magnetic fields obtained with the complex-coordinate-rotation method
Patrik Zielinski, Patric Rommel, Frank Schweiner +1
The complete theoretical description of experimentally observed magnetoexcitons in cuprous oxide has been achieved by F. Schweiner et al [Phys. Rev. B 95, 035202 (2017)], using a c…
Magneto-Stark-effect of yellow excitons in cuprous oxide
Patric Rommel, Frank Schweiner, Jörg Main +6
We investigate and compare experimental and numerical excitonic spectra of the yellow series in cuprous oxide CuO in the Voigt configuration and thus partially extend the resul…
Exciton-phonon interaction breaking all antiunitary symmetries in external magnetic fields
Frank Schweiner, Patric Rommel, Jörg Main +1
Recent experimental investigations by M. Aßmann et al. [Nature Mater. 15, 741 (2016)] on the spectrum of magnetoexcitons in cuprous oxide revealed the statistics of a Gaussian unit…