TY  - JOUR
A1  - Winkler, Karol
A1  - Fischer, Julian
A1  - Schade, Anne
A1  - Amthor, Matthias
A1  - Dall, Robert
A1  - Geßler, Jonas
A1  - Emmerling, Monika
A1  - Ostrovskaya, Elena A.
A1  - Kamp, Martin
A1  - Schneider, Christian
A1  - Höfling, Sven
T1  - A polariton condensate in a photonic crystal potential landscape
JF  - New Journal of Physics
N2  - The possibility of investigating macroscopic coherent quantum states in polariton condensates and of engineering polariton landscapes in semiconductors has triggered interest in using polaritonic systems to simulate complex many-body phenomena. However, advanced experiments require superior trapping techniques that allow for the engineering of periodic and arbitrary potentials with strong on-site localization, clean condensate formation, and nearest-neighbor coupling. Here we establish a technology that meets these demands and enables strong, potentially tunable trapping without affecting the favorable polariton characteristics. The traps are based on a locally elongated microcavity which can be formed by standard lithography. We observe polariton condensation with non-resonant pumping in single traps and photonic crystal square lattice arrays. In the latter structures, we observe pronounced energy bands, complete band gaps, and spontaneous condensation at the M-point of the Brillouin zone.
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-125050
VL  - 17
ER  - 
TY  - JOUR
A1  - Waldherr, Max
A1  - Lundt, Nils
A1  - Klaas, Martin
A1  - Betzold, Simon
A1  - Wurdack, Matthias
A1  - Baumann, Vasilij
A1  - Estrecho, Eliezer
A1  - Nalitov, Anton
A1  - Cherotchenko, Evgenia
A1  - Cai, Hui
A1  - Ostrovskaya, Elena A.
A1  - Kavokin, Alexey V.
A1  - Tongay, Sefaattin
A1  - Klembt, Sebastian
A1  - Höfling, Sven
A1  - Schneider, Christian
T1  - Observation of bosonic condensation in a hybrid monolayer MoSe2-GaAs microcavity
JF  - Nature Communications
N2  - Bosonic condensation belongs to the most intriguing phenomena in physics, and was mostly reserved for experiments with ultra-cold quantum gases. More recently, it became accessible in exciton-based solid-state systems at elevated temperatures. Here, we demonstrate bosonic condensation driven by excitons hosted in an atomically thin layer of MoSe2, strongly coupled to light in a solid-state resonator. The structure is operated in the regime of collective strong coupling between a Tamm-plasmon resonance, GaAs quantum well excitons, and two-dimensional excitons confined in the monolayer crystal. Polariton condensation in a monolayer crystal manifests by a superlinear increase of emission intensity from the hybrid polariton mode, its density-dependent blueshift, and a dramatic collapse of the emission linewidth, a hallmark of temporal coherence. Importantly, we observe a significant spin-polarization in the injected polariton condensate, a fingerprint for spin-valley locking in monolayer excitons. Our results pave the way towards highly nonlinear, coherent valleytronic devices and light sources.
KW  - polaritons
KW  - two-dimensional materials
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-233280
VL  - 9
ER  -