Entanglement Enhanced Thermometry in the Detection of the Unruh Effect

TL;DR

This paper demonstrates that entanglement can significantly improve the precision of detecting the Unruh effect using a relativistic quantum probe, with optimal detection occurring before thermal equilibrium is reached.

Contribution

It introduces a method leveraging entanglement to enhance Unruh effect detection sensitivity in a relativistic quantum system, optimizing measurement timing.

Findings

Entanglement increases detection sensitivity.

Maximum precision occurs before thermal equilibrium.

Optimal detection strategy involves equilibration with the thermal bath.

Abstract

We show how the use of entanglement can enhance the precision of the detection of the Unruh effect with an accelerated probe. We use the Unruh-DeWitt model of a two-level atom interacting relativistically with a quantum field and treat the atom as an open quantum system to derive the master equation governing its evolution. By means of quantum state discrimination, we detect the accelerated motion of the atom by examining its time evolving state. It turns out that the optimal strategy for the detection of the Unruh effect, to which the accelerated atom is sensitive, involves letting the atom-thermometer equilibrate with the thermal bath. However, introducing initial entanglement between the detector and an external degree of freedom leads to an enhancement of the sensitivity of the detector. Also, the maximum precision is attained within finite time, before equilibration takes place.