Thermalization of particle detectors: The Unruh effect and its reverse

TL;DR

This paper investigates the Anti-Unruh effect in stationary scenarios, revealing that accelerated detectors can cool down with increasing KMS temperature, a phenomenon unique to acceleration and not inertial motion.

Contribution

It demonstrates that the Anti-Unruh effect occurs for accelerated detectors in stationary states, even with adiabatic switching, and distinguishes it from inertial detector behavior.

Findings

Accelerated detectors can cool as KMS temperature increases.

The Anti-Unruh effect does not occur for inertial detectors.

The effect persists even with infinitely long adiabatic switching.

Abstract

We study the Anti-Unruh effect in general stationary scenarios. We find that, for accelerated trajectories, a particle detector coupled to a KMS state of a quantum field can cool down (click less often) as the KMS temperature increases. Remarkably, this is so even when the detector is switched on adiabatically for infinitely long times. We also show that the Anti-Unruh effect is characteristic of accelerated detectors, and cannot appear for inertially moving detectors (e.g., in a thermal bath).