Regensburg 2007 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 12: Quantum dots and wires: Optical properties I

HL 12.7: Vortrag

Montag, 26. März 2007, 16:30–16:45, H17

A Gallium Nitride Single-Photon Source Operating at 200 K — •Stephan Götzinger¹, Charles Santori¹, Yoshihisa Yamamoto¹, Satoshi Kako², Katsuyuki Hoshino², and Yasuhiko Arakawa² — ¹E. L. Ginzton Laboratory, Stanford University, Stanford, California 94305, U.S.A. — ²Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku. Tokyo,153-8505, Japan

Nitride semiconductors have emerged as important materials for blue and ultraviolet light-emitting diodes with numerous commercial applications. However, their large bandgaps make these materials also interesting for quantum information applications, such as quantum cryptography.

We report on a single-photon source based on a gallium nitride semiconductor quantum dot emitting at a record-short wavelength of 355nm. The power dependence of the second order coherence function suggests a two-level model for photon antibunching, where the antibunching timescale converges to the exciton decay time in the weak-excitation limit. This is supported by fluorescence lifetime measurements on single quantum dots. In temperature dependent measurements, photon antibunching was observed up to 200K, a temperature easily reachable with thermo-electric cooling [1].

[1] S. Kako et. al., Nature Materials 5, 887 (2006).