On the information behavior from quadratically coupled accelerated detectors

TL;DR

This paper investigates how quadratic coupling in accelerated quantum detectors affects information behavior, revealing that it amplifies the Unruh effect and accelerates information degradation compared to linear coupling.

Contribution

It provides a detailed comparison between quadratic and linear coupling in accelerated detectors, highlighting the impact on quantum information degradation and the role of coupling structure.

Findings

Quadratic coupling amplifies the Unruh effect.

Information degrades faster with quadratic coupling.

Coupling constant significantly influences information behavior.

Abstract

In this work, we propose to investigate the information behavior of quantum systems through accelerated detectors quadratically coupled with a massless scalar field. In addition, we made detailed comparisons with the case of linear coupling. The perturbative method was used to evolve the density matrix that describes the interaction of the detector-field system during a finite time. The systems studied were: accelerated single-qubit, quantum interferometric circuit, and the which-path distinguishability circuit. The results on the probability transition rates show that quadratic coupling amplifies the Unruh effect. This is due to the modification of the interaction structure, allowing the simultaneous absorption of multiple quanta. Our findings showed that the information is degraded more quickly in the case of quadratic coupling, when compared to the linear case. Furthermore, this change is mainly given by the coupling constant and by an additional factor that arises in the case of quadratic coupling. Therefore, these results indicate that the nature of the coupling between the detector and the field plays a fundamental role in the behavior of quantum information in high acceleration regimes.