2k citations
Counting papers with at most 25 authors, so collaboration author lists do not stand in for the people here.
- Centre National de la Recherche ScientifiqueFR75 papers
- University of MünsterDE37 papers
- Los Alamos National LaboratoryUS33 papers
- Max Planck Institute for Dynamics and Self-OrganizationDE26 papers
- Observatoire de la Côte d’AzurFR26 papers
- University of StuttgartDE25 papers
- Friedrich-Alexander-Universität Erlangen-NürnbergDE23 papers
- Heinrich Heine University DüsseldorfDE23 papers
- Northwestern UniversityUS23 papers
- Deutsches Elektronen-Synchrotron DESYDE22 papers
- Bogolyubov Institute for Theoretical PhysicsUA21 papers
- ETH ZurichCH21 papers
66 papers · 1 filter
Photon Number Coherence in Quantum Dot-Cavity Systems can be Enhanced by Phonons
Paul C. A. Hagen, Mathieu Bozzio, Moritz Cygorek +2
Semiconductor quantum dots are a versatile source of single photons with tunable properties to be used in quantum-cryptographic applications. A crucial figure of merit of the emitt…
Two-photon excitation with finite pulses unlocks pure dephasing-induced degradation of entangled photons emitted by quantum dots
Tim Seidelmann, Thomas K. Bracht, Barbara Ursula Lehner +7
Semiconductor quantum dots have emerged as an especially promising platform for the generation of polarization-entangled photon pairs. However, it was demonstrated recently that th…
Phonon-induced transition between entangled and nonentangled photon emission in constantly driven quantum-dot--cavity systems
Tim Seidelmann, Michael Cosacchi, Moritz Cygorek +3
Entangled photon pairs are essential for many applications in quantum technologies. Recent theoretical studies demonstrated that different types of entangled Bell states can be cre…
SUPER Scheme in Action: Experimental Demonstration of Red-detuned Excitation of a Quantum Dot
Yusuf Karli, Florian Kappe, Vikas Remesh +8
The quest for the perfect single-photon source includes finding the optimal protocol for exciting the quantum emitter. Based on a recently proposed, so-called SUPER (swing-up of qu…
Phonon wave packet emission during state preparation of a semiconductor quantum dot using different schemes
Thomas K. Bracht, Tim Seidelmann, Tilmann Kuhn +2
The carrier-phonon interaction in semiconductor quantum dots can greatly affect the optical preparation of the excited state. For resonant excitation used in the Rabi preparation s…
The optical Stark shift to control the dark exciton occupation of a quantum dot in a tilted magnetic field
Miriam Neumann, Florian Kappe, Thomas K. Bracht +5
When a detuned and strong laser pulse acts on an optical transition, a Stark shift of the corresponding energies occurs. We analyze how this optical Stark effect can be used to pre…
Schrödinger cats in quantum-dot--cavity systems
M. Cosacchi, T. Seidelmann, J. Wiercinski +4
A Schrödinger-cat state is a coherent superposition of macroscopically distinguishable quantum states, in quantum optics usually realized as superposition of coherent states. Proto…
On-demand generation of higher-order Fock states in quantum-dot--cavity systems
M. Cosacchi, J. Wiercinski, T. Seidelmann +4
The on-demand preparation of higher-order Fock states is of fundamental importance in quantum information sciences. We propose and compare different protocols to generate higher-or…
Transiently changing shape of the photon number distribution in a quantum-dot--cavity system driven by chirped laser pulses
M. Cosacchi, T. Seidelmann, F. Ungar +3
We have simulated the time evolution of the photon number distribution in a semiconductor quantum dot-microcavity system driven by chirped laser pulses and compare with unchirped r…
Spin dynamics of hot excitons in diluted magnetic semiconductors with spin-orbit interaction
Florian Ungar, Pablo Ignacio Tamborenea, Vollrath Martin Axt
We explore the impact of a Rashba-type spin-orbit interaction in the conduction band on the spin dynamics of hot excitons in diluted magnetic semiconductor quantum wells. In materi…
Role of excited states in the dynamics of excitons and their spins in diluted magnetic semiconductors
Florian Ungar, Moritz Cygorek, Vollrath Martin Axt
We theoretically investigate the impact of excited states on the dynamics of the exciton ground state in diluted magnetic semiconductor quantum wells. Exploiting the giant Zeeman s…
Emission-frequency separated high quality single-photon sources enabled by phonons
Michael Cosacchi, Florian Ungar, Moritz Cygorek +2
We demonstrate theoretically that the single-photon purity of photons emitted from a quantum dot exciton prepared by phonon-assisted off-resonant excitation can be significantly hi…
Phonon-induced enhancement of photon entanglement in quantum dot-cavity systems
Tim Seidelmann, Florian Ungar, Andreas M. Barth +4
We report on simulations of the degree of polarization entanglement of photon pairs simultaneously emitted from a quantum dot-cavity system that demand revisiting the role of phono…
Origins of overshoots in the exciton spin dynamics in semiconductors
Florian Ungar, Moritz Cygorek, Vollrath Martin Axt
We investigate the origin of overshoots in the exciton spin dynamics after resonant optical excitation. As a material system, we focus on diluted magnetic semiconductor quantum wel…
From strong to weak temperature dependence of the two-photon entanglement resulting from the biexciton cascade inside a cavity
Tim Seidelmann, Florian Ungar, Moritz Cygorek +4
We investigate the degree of entanglement quantified by the concurrence of photon pairs that are simultaneously emitted in the biexciton-exciton cascade from a quantum dot in a cav…
Phonon-induced quantum ratchet in the exciton spin dynamics in diluted magnetic semiconductors in a magnetic field
Florian Ungar, Moritz Cygorek, Vollrath Martin Axt
Magnetically doped semiconductors are well known for their giant Zeeman splittings which can reach several meV even in relatively small external magnetic fields. After preparing a…
Phonon impact on the dynamics of resonantly excited and hot excitons in diluted magnetic semiconductors
Florian Ungar, Moritz Cygorek, Vollrath Martin Axt
Phonons are well known to be the main mechanism for the coupling between bright and dark excitons in nonmagnetic semiconductors. Here, we investigate diluted magnetic semiconductor…
Many-body correlations brought to light in absorption spectra of diluted magnetic semiconductors
Florian Ungar, Moritz Cygorek, Vollrath Martin Axt
Diluted magnetic semiconductors are materials well known to exhibit strong correlations which typically manifest in carrier-mediated magnetic ordering. In this Rapid Communication,…
Path-integral approach for nonequilibrium multi-time correlation functions of open quantum systems coupled to Markovian and non-Markovian environments
Michael Cosacchi, Moritz Cygorek, Florian Ungar +3
Using a real-time path integral approach we develop an algorithm to calculate multi-time correlation functions of open few-level quantum systems that is applicable to highly nonequ…
Trend reversal in the magnetic-field dependence of exciton spin-transfer rates in diluted magnetic semiconductors due to non-Markovian dynamics
Florian Ungar, Moritz Cygorek, Vollrath Martin Axt
We investigate theoretically the influence of an external magnetic field on the spin dynamics of excitons in diluted magnetic semiconductor quantum wells. To this end, we apply a q…
Localization of magnon modes in a curved magnetic nanowire
Yuri Gaididei, Volodymyr P. Kravchuk, Franz G. Mertens +4
Spin waves in magnetic nanowires can be bound by a local bending of the wire. The eigenfrequency of a truly local magnon mode is determined by the curvature: a general analytical e…
Comparison of different concurrences characterizing photon-pairs generated in the biexciton cascade in quantum dots coupled to microcavities
Moritz Cygorek, Florian Ungar, Tim Seidelmann +4
We compare three different notions of concurrence to measure the polarization entanglement of two-photon states generated by the biexciton cascade in a quantum dot embedded in a mi…
Nonlinear cavity feeding and unconventional photon statistics in solid-state cavity QED revealed by many-level real-time path-integral calculations
Moritz Cygorek, Andreas M. Barth, Florian Ungar +2
The generation of photons in a microcavity coupled to a laser-driven quantum dot interacting with longitudinal acoustic (LA) phonons is studied in the regime of simultaneously stro…
Quantum kinetic equations for the ultrafast spin dynamics of excitons in diluted magnetic semiconductor quantum wells after optical excitation
Florian Ungar, Moritz Cygorek, Vollrath Martin Axt
Quantum kinetic equations of motion for the description of the exciton spin dynamics in II-VI diluted magnetic semiconductor quantum wells with laser driving are derived. The model…