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  - Kochereshko, Vladimir P.
A1  - Durnev, Mikhail V.
A1  - Besombes, Lucien
A1  - Mariette, Henri
A1  - Sapega, Victor F.
A1  - Askitopoulos, Alexis
A1  - Savenko, Ivan G.
A1  - Liew, Timothy C. H.
A1  - Shelykh, Ivan A.
A1  - Platonov, Alexey V.
A1  - Tsintzos, Simeon I.
A1  - Hatzopoulos, Z.
A1  - Savvidis, Pavlos G.
A1  - Kalevich, Vladimir K.
A1  - Afanasiev, Mikhail M.
A1  - Lukoshkin, Vladimir A.
A1  - Schneider, Christian
A1  - Amthor, Matthias
A1  - Metzger, Christian
A1  - Kamp, Martin
A1  - Hoefling, Sven
A1  - Lagoudakis, Pavlos
A1  - Kavokin, Alexey
T1  - Lasing in Bose-Fermi mixtures
JF  - Scientific Reports
N2  - Light amplification by stimulated emission of radiation, well-known for revolutionising photonic science, has been realised primarily in fermionic systems including widely applied diode lasers. The prerequisite for fermionic lasing is the inversion of electronic population, which governs the lasing threshold. More recently, bosonic lasers have also been developed based on Bose-Einstein condensates of exciton-polaritons in semiconductor microcavities. These electrically neutral bosons coexist with charged electrons and holes. In the presence of magnetic fields, the charged particles are bound to their cyclotron orbits, while the neutral exciton-polaritons move freely. We demonstrate how magnetic fields affect dramatically the phase diagram of mixed Bose-Fermi systems, switching between fermionic lasing, incoherent emission and bosonic lasing regimes in planar and pillar microcavities with optical and electrical pumping. We collected and analyzed the data taken on pillar and planar microcavity structures at continuous wave and pulsed optical excitation as well as injecting electrons and holes electronically. Our results evidence the transition from a Bose gas to a Fermi liquid mediated by magnetic fields and light-matter coupling.
KW  - Bose-Fermi
KW  - magnetic fields
KW  - Bose gas
KW  - Fermi liquid
KW  - light-matter coupling
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-168152
VL  - 6
IS  - 20091
ER  - 
TY  - JOUR
A1  - Amthor, Matthias
A1  - Weißenseel, Sebastian
A1  - Fischer, Julian
A1  - Kamp, Martin
A1  - Schneider, Christian
A1  - Höfling, Sven
T1  - Electro-optical switching between polariton and cavity lasing in an InGaAs quantum well microcavity
N2  - We report on the condensation of microcavity exciton polaritons under optical excitation in a microcavity with four embedded InGaAs quantum wells. The polariton laser is characterized by a distinct nonlinearity in the input-output-characteristics, which is accompanied by a drop of the emission linewidth indicating temporal coherence and a characteristic persisting emission blueshift with increased particle density. The temporal coherence of the device at threshold is underlined by a characteristic drop of the second order coherence function to a value close to 1. Furthermore an external electric field is used to switch between polariton regime, polariton condensate and photon lasing.
KW  - Quantum-well, -wire and -dot devices
KW  - Scattering
KW  - stimulated
KW  - Resonators
KW  - Microcavity devices
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-111130
ER  -