Stationary inversion of a two level system coupled to an off-resonant cavity with strong dissipation

TL;DR

This paper demonstrates a scheme for achieving significant stationary inversion in a two-level system coupled to an off-resonant cavity, leveraging multi-photon resonances to enhance nonlinear cavity QED effects even in semiconductor environments.

Contribution

It introduces an off-resonant excitation method that achieves high stationary inversion via cavity-assisted two-photon resonance, applicable in realistic, dissipative semiconductor systems.

Findings

Achieved exciton populations >0.75 under realistic decay conditions

Predicted experimental signatures in fluorescence and correlation functions

Enhanced multi-photon cavity QED effects in off-resonant, dissipative environments

Abstract

We present an off-resonant excitation scheme that realizes pronounced stationary inversion in a two level system. The created inversion exploits a cavity-assisted two photon resonance to enhance the multi-photon regime of nonlinear cavity QED and survives even in a semiconductor environment, where the cavity decay rate is comparable to the cavity-dot coupling rate. Exciton populations of greater than 0.75 are obtained in the presence of realistic decay and pure dephasing. Quantum trajectory simulations and quantum master equation calculations help elucidate the underlying physics and delineate the limitations of a simplified rate equation model. Experimental signatures of inversion and multi-photon cavity QED are predicted in the fluorescence intensity and second-order correlation function measured as a function of drive power.