Optimal quantum estimation of the Unruh-Hawking effect

TL;DR

This paper investigates the optimal quantum measurement strategies for detecting the Unruh-Hawking effect, demonstrating that high-energy scalar fields enhance observability and that photon counting with Fock states achieves ultimate sensitivity.

Contribution

It establishes the optimal quantum detection method for the Unruh-Hawking effect using Fock states and photon counting, identifying conditions for experimental observation.

Findings

High-energy scalar fields amplify the effect

Photon counting with Fock states is optimal

Parameter regimes for reliable detection identified

Abstract

We address on general quantum-statistical grounds the problem of optimal detection of the Unruh-Hawking effect. We show that the effect signatures are magnified up to potentially observable levels if the scalar field to be probed has high mean energy from an inertial perspective: The Unruh-Hawking effect acts like an amplification channel. We prove that a field in a Fock inertial state, probed via photon counting by a non-inertial detector, realizes the optimal strategy attaining the ultimate sensitivity allowed by quantum mechanics for the observation of the effect. We define the parameter regime in which the effect can be reliably revealed in laboratory experiments, regardless of the specific implementation.