Berlin 2012 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 74: Focus Session: Semiconductor-based Quantum Communication I
HL 74.5: Topical Talk
Thursday, March 29, 2012, 12:00–12:30, ER 164
Towards On-Chip Quantum Optics using Superconducting Single Photon Detectors coupled to Photonic Crystal Waveguides — •Günther Reithmaier1, Jörg Senf1, Arne Laucht2, Max Bichler1, Rudolf Gross3, and Jonathan Finley1 — 1Walter Schottky Institut, TU München, Germany — 2Centre for Quantum Computation Communication Technology, Sydney, Australia — 3Walther-Meißner-Institut, TU München, Germany
We report on-chip generation of single photons in a GaAs 2D photonic crystal waveguide (PCW) and progress towards integration with NbN superconducting nanowire single photon detectors (SNSPDs) [2]. Single self-assembled InGaAs QDs inside the waveguide are located using spatially resolved microscopy. Detection from the waveguide facet shows a 55x more efficient coupling to the PWG mode compared to detection along an axis perpendicular to the sample surface. Time-resolved PL measurements show that the fraction of all spontaneous emission emitted into the waveguide mode is 85-96% and clean single photon emission is observed. We also describe first steps to integrate SNSPDs directly onto such a GaAs photonic crystal. SNSPDs combine high detection efficiency, low dark count rates and picosecond timing resolution [1], properties that depend strongly on the crystal quality of the NbN film [2]. By optimizing the nitrogen pressure and substrate temperature, NbN films on GaAs exhibit a superconducting Tc=11.2K and ΔT=0.5K. [1]G. N. Goltsman et al., APL 79,6 (2001) [2]F. Marsili et al., Supercond. Sci. Technol. 22 (2009) 095013