Intrinsic and environmental effects on the interference properties of a high-performance quantum dot single-photon source

Stefan Gerhardt, Jake Iles-Smith, Dara McCutcheon, Yu-Ming He, Sebastian Unsleber, Simon Betzold, Niels Gregersen, Jesper Mørk, Sven Höfling, Christian Schneider

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We report a joint experimental and theoretical study of the interference properties of a single-photon source based on a In(Ga)As quantum dot embedded in a quasiplanar GaAs microcavity. Using resonant laser excitation with a pulse separation of 2 ns, we find near-perfect interference of the emitted photons, and a
corresponding indistinguishability of I = (99.6 + 0.4 − 1.4)%. For larger pulse separations, quasiresonant excitation conditions, increasing pump power, or with increasing temperature, the interference contrast is progressively and notably reduced. We present a systematic study of the relevant dephasing mechanisms and explain our results in the framework of a microscopic model of our system. For strictly resonant excitation, we show that photon indistinguishability is independent of pump power, but strongly influenced by virtual phonon-assisted processes which are not evident in excitonic Rabi oscillations.
Original languageEnglish
Article number195432
JournalPhysical Review B (Condensed Matter and Materials Physics)
Number of pages10
Publication statusPublished - 2018

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