Berlin 2012 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 82: Focus Session: Semiconductor-based Quantum Communication II

HL 82.3: Topical Talk

Thursday, March 29, 2012, 16:00–16:30, ER 164

Coherence and photon statistics of the Mollow triplet sideband emission of a quantum dot — •Sven M. Ulrich, Ata Ulhaq, Stefanie Weiler, and Peter Michler — Institut für Halbleiteroptik und Funktionelle Grenzflächen (IHFG), Universität Stuttgart

Analysis and minimization of dephasing processes in quantum light emitters is a central research issue for future quantum information processing schemes. Single quantum dot (QD) resonance fluorescence has proven to be nearly Fourier transform-limited for excitation powers below emitter saturation [1]. Here we present detailed investigations of QD resonance emission above saturation, where the 'dressed' character confirms by the so-called Mollow triplet. Single InGaAs/GaAs QDs in planar waveguide structures and high-quality pillar cavities have been studied. By high-resolution photoluminescence, we trace Mollow triplet spectra under variable excitation powers and detuning conditions. Photon correlation measurements demonstrate both 'single' and 'cascaded' emission from the Mollow triplet sidebands. By laser detuning the very bright emission can be frequency-tuned over 15 times its linewidth. Furthermore, the effect of dephasing in terms of systematic spectral broadening of the triplet sidebands and oscillation damping in g(1) coherence are observed as a strong fingerprint of excitation-induced dephasing [2]. Our results are consistent with predictions of a recently presented model on phonon-dressed QD Mollow triplet emission in the cavity QED regime [3]. [1] S. Ates et al., Phys. Rev. Lett. 103, 167402 (2009). [2] S.M. Ulrich et al., Phys. Rev. Lett. 106, 247402 (2011). [3] C. Roy and S. Hughes, Phys. Rev. Lett. 106, 247403 (2011).