Exploring Dephasing of a Solid-State Quantum Emitter via Time- and Temperature- Dependent Hong-Ou-Mandel Experiments

TL;DR

This study investigates how the indistinguishability of photons from a semiconductor quantum dot varies with time and temperature using two-photon interference experiments, revealing non-Markovian noise effects and phonon-induced dephasing.

Contribution

It provides direct, time-resolved insights into the coherence and dephasing mechanisms of quantum emitters at nanosecond scales, advancing understanding of photon indistinguishability.

Findings

TPI visibility decreases with temporal separation and temperature.

Non-Markovian noise from charge-traps explains visibility decay.

Phonon-induced dephasing reduces visibility from 96% at 10K to zero at 40K.

Abstract

We probe the indistinguishability of photons emitted by a semiconductor quantum dot (QD) via time- and temperature- dependent two-photon interference (TPI) experiments. An increase in temporal-separation between consecutive photon emission events, reveals a decrease in TPI visibility on a nanosecond timescale, theoretically described by a non-Markovian noise process in agreement with fluctuating charge-traps in the QD's vicinity. Phonon-induced pure dephasing results in a decrease in TPI visibility from $(96\pm4)\,$\% at 10\,K to a vanishing visibility at 40\,K. In contrast to Michelson-type measurements, our experiments provide direct access to the time-dependent coherence of a quantum emitter at a nanosecond timescale.