Dephasing-assisted Gain and Loss in Mesoscopic Quantum Systems

TL;DR

This paper investigates how dephasing-assisted dissipative processes influence the steady-state gain and loss in a microwave resonator coupled to a double quantum-dot, providing a more accurate theoretical model aligned with recent experiments.

Contribution

It introduces a comprehensive analysis of dephasing effects using fourth-order Lindblad dissipators, extending beyond existing polaronic theories to better match experimental data.

Findings

Dephasing significantly impacts resonator gain and loss.

Theoretical results align well with experimental observations.

Dephasing-assisted processes are crucial for accurate modeling.

Abstract

Motivated by recent experiments, we analyse the phonon-assisted steady-state gain of a microwave field driving a double quantum-dot in a resonator. We apply the results of our companion paper, which derives the complete set of fourth-order Lindblad dissipators using Keldysh methods, to show that resonator gain and loss are substantially affected by dephasing-assisted dissipative processes in the quantum-dot system. These additional processes, which go beyond recently proposed polaronic theories, are in good quantitative agreement with experimental observations