On-demand semiconductor source of 780 nm single photons with controlled temporal wave packets

TL;DR

This paper presents a fast, tunable single-photon source at 780 nm using a GaAs quantum dot, capable of producing photons with tailored temporal profiles and low multi-photon probability, advancing hybrid quantum interfaces.

Contribution

The work introduces a novel on-demand, bandwidth-tunable single-photon source with controlled temporal wave packets based on spin-flip Raman transitions in GaAs quantum dots.

Findings

Single photons generated at 780 nm with tailored temporal profiles.

Low multi-photon emission probability ($g^{2}(0) \,\sim\, 0.10-0.15$).

Narrow linewidth Raman photons (as low as 200 MHz).

Abstract

We report on a fast, bandwidth-tunable single-photon source based on an epitaxial GaAs quantum dot. Exploiting spontaneous spin-flip Raman transitions, single photons at $780\,$nm are generated on-demand with tailored temporal profiles of durations exceeding the intrinsic quantum dot lifetime by up to three orders of magnitude. Second-order correlation measurements show a low multi-photon emission probability ($g^{2}(0)\sim\,0.10-0.15$) at a generation rate up to $10\,$MHz. We observe Raman photons with linewidths as low as $200\,$MHz, narrow compared to the $1.1\,$GHz linewidth measured in resonance fluorescence. The generation of such narrow-band single photons with controlled temporal shapes at the rubidium wavelength is a crucial step towards the development of an optimized hybrid semiconductor-atom interface.