Berlin 2015 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 109: Quantum dots and wires: Quantum communication and quantum information science
HL 109.8: Talk
Friday, March 20, 2015, 13:00–13:15, ER 164
Fiber-coupled quantum dot based single-photon sources operated by a Stirling cryocooler — •Alexander Schlehahn, Esra Tauscher, Thomay Megas, Manuel Gschrey, Jan-Hindrik Schulze, André Strittmatter, Sven Rodt, Tobias Heindel, and Stephan Reitzenstein — Technische Universität Berlin, Institut für Festkörperphysik, 10623 Berlin, Germany
Easy-to-operate single-photon sources are one of the key components in quantum communication. Up till now such non-classical light sources have been operated almost exclusively in shielded lab-environments and practical concepts appeared elusive. Here we report on the application of a compact and user-friendly Stirling cryocooler in the field of nanophotonics. It is capable of operating single-photon emitters at a base temperature well below 30 K with high purity (g(2)(0)=0.04), while offering cost efficiency and independence from liquid helium supply. A method for direct fiber coupling of single quantum emitters inside the Stirling cryostat is introduced. Sample alignment is obtained by an innovative two-step deep-etching process for GaAs. It allows us to deterministically position single quantum dot structures within a few tens of micrometers precision on a 2.5 mm diameter, racket-shaped sample. Mounting sample and fiber into standard ceramic fiber sleeves with sub-micrometer diameter deviation achieves excellent alignment of fiber core and mesa. Laser excitation and quantum dot emission are guided via the same optical fiber, leading to a drift- and vibration-unaffected signal. This demonstration paves the way towards user-friendly and high-quality table-top non-classical light sources.