The fluctuation-dissipation relation in a resonantly driven quantum medium

TL;DR

This paper investigates how a coherently driven quantum medium exhibits modified noise characteristics and violates the standard fluctuation-dissipation relation due to nonlinear noise exchange.

Contribution

It introduces a field-induced modification of the fluctuation-dissipation relation in a resonantly driven quantum medium, highlighting nonlinear noise effects.

Findings

Significant modification of noise-damping relation due to external driving

Violation of standard fluctuation-dissipation theorem in the system

Nonlinear noise exchange between atomic frequencies observed

Abstract

We calculate the radiation noise level associated with the spontaneous emission of a coherently driven medium. The significant field-induced modification of relation between the noise power and damping constant in a thermal reservoir is obtained. The nonlinear noise exchange between different atomic frequencies leads to violation of standard relations dictated by the fluctuation-dissipation theorem.