Field assisted extraction and swelling of quantum coherence for moving Unruh-DeWitt detectors

TL;DR

This paper investigates how motion, including constant speed and acceleration, can enhance the quantum coherence extracted by an Unruh-DeWitt detector interacting with a scalar field, revealing a phenomenon called 'coherence swelling.'

Contribution

It introduces the concept of coherence swelling in moving detectors and analyzes how motion influences quantum coherence extraction in quantum field interactions.

Findings

Coherence can be larger for moving detectors than at rest under certain conditions.

Swelling of coherence increases with velocity or acceleration, especially for short interaction durations.

Moving detectors can retain coherence longer, reducing the rate of coherence loss.

Abstract

We study the effects of motion for an Unruh-DeWitt detector, modeled as a two-level system, on the amount of coherence extracted, when it interacts with a massless scalar coherent field in 1+1 Minkowski spacetime. We observe that compared to a detector at rest, for certain values of the initial energy of the field and the interaction duration, the amount is larger for both a detector moving with a constant speed or uniform acceleration. This "swelling" of coherence, which becomes more intense for increasing values of velocity or acceleration, is mostly observed for short durations, when the energy of the field is larger compared to that of the detector, and for longer durations but smaller field energies. As a consequence, the rate at which coherence is lost, is sometimes slower for a moving detector than for a detector at rest.