Dresden 2014 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 52: Focus Session: Quantum Light Sources Based on Solid State Systems: Status and Visions II (organized by HL)
TT 52.5: Vortrag
Dienstag, 1. April 2014, 15:15–15:30, POT 251
On-demand single-photon emission from electrically pumped, site-controlled quantum dots based on buried stressors — •Alexander Schlehahn, Waldemar Unrau, David Quandt, Jan-Hindrik Schulze, Tobias Heindel, Tim D. Germann, Ole Hitzemann, Udo W. Pohl, Dieter Bimberg, André Strittmatter, and Stephan Reitzenstein — Institut für Festkörperphysik, TU Berlin, Hardenbergstraße 36, 10623 Berlin, Germany
Single photons, emitted on demand, is one of the most basic needs in quantum information technology. We present pulsed operation of a lately introduced electrically driven source based on single quantum dots, deterministically aligned to a strain-inducing and current-path-restricting oxide aperture. The aperture is formed by oxidation of an AlAs/AlGaAs sandwich structure. The modification of its crystalline structure leads to geometry dependent strain in the topping GaAs-layer. Due to this strain modulation at the surface, an accumulation of quantum dots occurs above the aperture when depositing InGaAs. These QDs show excellent optical properties regarding the emission linewidth (FWHM < 25 µeV) and the single photon purity (g(2)(0) < 0.05), and outclass the reported characteristics of QDs grown by other prepositioning methods. The sample characterization is facilitated by an automatized micro-electroluminescence setup which includes a He-flow cryostat with an internal high-frequency probe in combination with a precise x-y-z-stage. This system allows for efficient sample testing without the need for wire bonding.