Single-photon superradiance from a quantum dot

TL;DR

This paper demonstrates single-photon superradiance in a semiconductor quantum dot, achieving a five-fold enhancement of oscillator strength, with potential for even greater enhancement at lower temperatures.

Contribution

It reports the first observation of superradiance in a quantum dot, using anharmonic spectrum manipulation to prepare superradiant states deterministically.

Findings

Five-fold increase in oscillator strength compared to typical quantum dots

Superradiant state can be prepared deterministically with laser pulses

Potential for oscillator strengths exceeding 1000 at lower temperatures

Abstract

We report on the observation of single-photon superradiance from an exciton in a semiconductor quantum dot. The confinement by the quantum dot is strong enough for it to mimic a two-level atom, yet sufficiently weak to ensure superradiance. The electrostatic interaction between the electron and the hole comprising the exciton gives rise to an anharmonic spectrum, which we exploit to prepare the superradiant quantum state deterministically with a laser pulse. We observe a five-fold enhancement of the oscillator strength compared to conventional quantum dots. The enhancement is limited by the base temperature of our cryostat and may lead to oscillator strengths above 1000 from a single quantum emitter at optical frequencies.