Discriminating quantum field theories in non-inertial frames

TL;DR

This paper uses quantum channel discrimination to improve methods for detecting the Unruh effect, showing that coherent state probes significantly enhance the ability to distinguish the effect in non-inertial frames, potentially enabling feasible experimental tests.

Contribution

It introduces optimized quantum strategies, especially using coherent states, to improve the discrimination of the Unruh effect, reducing required accelerations for detection.

Findings

Coherent state probes exponentially improve Unruh channel discrimination.

Using short laser pulses reduces necessary accelerations by over three orders of magnitude.

Enhanced discrimination methods can facilitate experimental tests of quantum field theory in curved spacetime.

Abstract

Quantum channel discrimination is used to test quantum field theory in non-inertial frames. We search for optimal strategies which can best see the thermality of the Unruh effect. We find that the usual strategy of counting particles in the vacuum can be improved, thereby enhancing the discrimination. Coherent state probes, which are practical and feasible, give exponential improvement in the discrimination of the Unruh channel and come very close to optimal. In particular, we show that using a short pulse laser, the accelerations required to test the Unruh effect can be reduced by at least three orders of magnitude with the same statistical confidence as could be achieved in vacuum. These results are expected to be relevant to upcoming experimental tests of quantum field theory in curved spacetimes in analogue systems.