Noise spectrum of a quantum dot-resonator lasing circuit

TL;DR

This paper investigates the noise characteristics of a quantum dot-resonator system in the lasing regime, revealing how transport current noise varies and encodes information about the system's coherent dynamics.

Contribution

It provides a detailed analysis of the noise spectrum and shot noise behavior in a quantum dot-resonator lasing circuit, highlighting new insights into the system's quantum coherence and transport properties.

Findings

Super-Poissonian shot noise near lasing transition

Sub-Poissonian noise deep in the lasing state

Resonance-structured noise spectrum revealing photon excitation

Abstract

Single-electron tunneling processes through a double quantum dot can induce a lasing state in an electromagnetic resonator which is coupled coherently to the dot system. Here we study the noise properties of the transport current in the lasing regime, i.e., both the zero-frequency shot noise as well as the noise spectrum. The former shows a remarkable super-Poissonian behavior when the system approaches the lasing transition, but sub-Poissonian behavior deep in the lasing state. The noise spectrum contains information about the coherent dynamics of the coupled dot-resonator system. It shows pronounced structure at a frequency matching that of the resonator due to the excitation of photons. For strong interdot Coulomb interaction we find asymmetries in the auto-correlation noise spectra of the left and right junctions, which we trace back to asymmetries in the incoherent tunneling channels.