TY  - JOUR
A1  - Tempel, Jean-Sebastian
A1  - Veit, Tempel
A1  - Assmann, Marc
A1  - Kreilkamp, Lars Erik
A1  - Höfling, Sven
A1  - Kamp, Martin
A1  - Forchel, Alfred
A1  - Bayer, Manfred
T1  - Temperature dependence of pulsed polariton lasing in a GaAs microcavity
JF  - New Journal of Physics
N2  - The second-order correlation function g\(^2\)(\(\tau\) = 0), input-output curves and pulse duration of the emission from a microcavity exciton-polariton system subsequent to picosecond-pulsed excitation are measured for different temperatures. At low temperatures a two-threshold behaviour emerges, which has been attributed to the onset of polariton lasing and conventional lasing at the first and the second threshold, respectively. We observe that polariton lasing is stable up to temperatures comparable with the exciton binding energy. At higher temperatures a single threshold displays the direct transition from thermal emission to photon lasing.
KW  - semiconductor microavity
KW  - quantized vortices
KW  - cavity polaritons
KW  - room temperature
KW  - excitons
KW  - time
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-134022
VL  - 14
IS  - 083014
ER  - 
TY  - JOUR
A1  - Fuchs, F.
A1  - Stender, B.
A1  - Trupke, M.
A1  - Simin, D.
A1  - Pflaum, J.
A1  - Dyakonov, V.
A1  - Astakhov, G.V.
T1  - Engineering near-infrared single-photon emitters with optically active spins in ultrapure silicon carbide
JF  - Nature Communications
N2  - Vacancy-related centres in silicon carbide are attracting growing attention because of their appealing optical and spin properties. These atomic-scale defects can be created using electron or neutron irradiation; however, their precise engineering has not been demonstrated yet. Here, silicon vacancies are generated in a nuclear reactor and their density is controlled over eight orders of magnitude within an accuracy down to a single vacancy level. An isolated silicon vacancy serves as a near-infrared photostable single-photon emitter, operating even at room temperature. The vacancy spins can be manipulated using an optically detected magnetic resonance technique, and we determine the transition rates and absorption cross-section, describing the intensity-dependent photophysics of these emitters. The on-demand engineering of optically active spins in technologically friendly materials is a crucial step toward implementation of both maser amplifiers, requiring high-density spin ensembles, and qubits based on single spins.
KW  - nuclear magnetic resonance
KW  - coherent control
KW  - 4H
KW  - phosphorus
KW  - qubits
KW  - defects
KW  - entanglement
KW  - room temperature
KW  - vacancy
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-148502
VL  - 6
IS  - 7578
ER  -