Deterministic single-photon source with on-chip 5.6 GHz acoustic clock

TL;DR

This paper demonstrates a scalable solid-state single-photon source using a quantum dot integrated in a microcavity, where GHz-frequency acoustic modulation enhances emission via the dynamic Purcell effect, enabling high-rate triggered single-photon emission.

Contribution

It introduces a hybrid photon-phonon microcavity platform that achieves GHz-frequency acoustic control of quantum dot emission for scalable single-photon sources.

Findings

Achieved modulation of quantum dot energy at up to 14 GHz.

Demonstrated enhancement of single-photon emission at 5.6 GHz.

Enabled on-chip tunable acoustic clocks exceeding several GHz.

Abstract

Scalable solid state single-photon sources (SPSs) with triggered single-photon emission rates exceeding a few GHz would aid in the wide technological adoption of photonic quantum technologies. We demonstrate triggering of a quantum dot (QD) single photon emission using dynamic Purcell effect induced at a frequency of several GHz by acoustic strain. To this end, InAs QDs are integrated in a hybrid photon-phonon patterned microcavity, where the density of optical states is tailored by the lateral confinement of photons in um-sized traps defined lithographically in the microcavity spacer. The single-photon character of the emission form a QD in a trap is confirmed by measuring single-photon statistics. We demonstrate modulation of the QD transition energy in a trap with a frequency up to 14 GHz by monochromatic longitudinal bulk acoustic phonons generated by piezoelectric transducers. For the modulation frequency of 5.6 GHz, corresponding to the acoustic mode of the microcavity, the QD energy is periodically shifted through a spectrally narrow confined photonic mode leading to an appreciable enhancement of the QD emission due to the dynamic Purcell effect. The platform thus enables the implementation of scalable III-V-based SPSs with on-chip tunable acoustic clocks with frequencies that can exceed several GHz under continuous wave optical excitation.