Estimation precision of parameter associated with Unruh-like effect

TL;DR

This paper investigates the quantum Fisher information related to acceleration and temperature in open quantum systems, revealing how boundaries and initial states influence the detection sensitivity of Unruh-like effects.

Contribution

It provides a detailed analysis of QFI behavior for a two-level atom under various conditions, highlighting the effects of boundaries and initial states on detection capabilities.

Findings

QFI peaks depend on initial states and boundary conditions.

Detection range of acceleration is expanded with a boundary.

QFI behavior varies with initial state and time evolution.

Abstract

We study the quantum Fisher information (QFI) of acceleration, in the open quantum systems, for a two-level atom with the circular motion coupled to a massless scalar field in the Minkowski vacuum without and with a reflecting boundary in the ultra-relativistic limit. As we amplify $a$, the saturation time decreases for $\theta\neq\pi$, but first increases and then decreases for $\theta=\pi$. Without a boundary, there exists a peak value of QFI with a certain time. The QFI varies with the initial state parameter $\theta$, and firstly takes peak value in the ground state of the atom. The variation of QFI with respect to $\theta$ gradually fades away with the evolution of time. With a boundary, the detection range of acceleration has been expanded. The QFI firstly takes the maximum in the excited state of the atom. In addition, we study the QFI of temperature for a static atom immersed in a thermal bath without and with a boundary. The relation between the saturation time and $T$ is similar to $a$. Without a boundary, the QFI of temperature is similar to that of acceleration. With a boundary, the QFI firstly takes peak value in the ground state of the atom, which is different from the behavior of acceleration. The results provide references for the detection of Unruh-like effect.