Sub-Poissonian photon statistics in a strongly coupled single-qubit laser

TL;DR

This paper explores the photon statistics in a strongly coupled qubit laser, revealing sub-Poissonian photon distributions when the coupling exceeds quasiparticle tunneling rates, indicating non-classical light emission.

Contribution

It demonstrates sub-Poissonian photon statistics in a strongly coupled single-qubit laser with a Cooper-pair box, a novel regime for non-classical light generation.

Findings

Photon number distribution is sub-Poissonian in the strong coupling limit.

Strong coupling exceeds quasiparticle tunneling rate, enabling non-classical light.

Qubit lasing with population inversion established via a third state.

Abstract

We investigate qubit lasing in the strong coupling limit. The qubit is given by a Cooper-pair box, and population inversion is established by an additional third state, which can be addressed via quasiparticle tunneling. The coupling strength between oscillator and qubit is assumed to be much higher than the quasiparticle tunneling rate. We find that the photon number distribution is sub-Poissonian in this strong coupling limit.