Dresden 2009 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 39: Quantum dots: Optical and transport properties
HL 39.4: Vortrag
Donnerstag, 26. März 2009, 10:15–10:30, BEY 81
Electrically Tunable Single Quantum Dot - Photonic Crystal Nanocavity Systems in the Strong Coupling Regime — •Norman Hauke, Arne Laucht, Felix Hofbauer, Gerhard Böhm, Markus-Christian Amann, and Jonathan James Finley — Walter-Schottky-Institut, Garching, Germany
We present investigations of electrically tunable single quantum dot (QD) - photonic crystal (PC) nanocavity systems, operating in the strong coupling regime. The sample consists of a single layer of In0.4Ga0.6As self-assembled QDs embedded in the center of a 180nm thick p-i-n GaAs membrane, which is patterned by electron beam lithography and reactive ion etching to form a PC slab with a L3 defect nanocavity. Gold contacts are evaporated for electrical access, thus allowing us to create electric fields in the intrinsic GaAs region. By making use of the quantum confined Stark-effect, we can reversibly tune the optical emission of a single exciton into and out of spectral resonance with a nanocavity mode (Q ≈ 11000) at ≈ 1200 meV.
Optical measurements were performed by using low temperature confocal microscopy. In photoluminescence experiments, we observe a clear anticrossing between exciton and mode emission (vacuum Rabi splitting ≈ 70-130 µ eV), which is a signature for strong coupling between emitter and cavity. We further investigated the pump power and temperature dependence of the vacuum Rabi-splitting, showing that dephasing processes destroy the strong interaction for high pump powers or high temperatures.
Supported financially by the DFG via SFB-631 and NIM