Unruh acceleration effect on the precision of parameter estimation

TL;DR

This paper analyzes how Unruh acceleration affects the Fisher information in quantum systems, revealing that acceleration generally depletes information and impacts parameter estimation precision, with some states maintaining constant information over certain acceleration ranges.

Contribution

It provides an analytical solution for Fisher information dynamics under Unruh acceleration, highlighting the entanglement-dependent depletion and conditions for optimal estimation.

Findings

Unruh acceleration depletes Fisher information.

Fisher information can remain constant over certain acceleration intervals.

Parameter estimation precision decreases with increasing acceleration.

Abstract

The dynamics of Fisher information for an accelerated system initially prepared in the $X$-state is discussed. An analytical solution, which consists of three parts: classical, the average over all pure states and a mixture of pure states is derived for the general state and for Werner state. It is shown that, the Unruh acceleration has a depleting effect on the Fisher information. This depletion depends on the degree of entanglement of the initial state settings. For the $X$-state, for some intervals of Unruh acceleration, the Fisher information remains constant, irrespective to the Unruh acceleration. In general, the possibility of estimating the state's parameters decreases as the acceleration increases. However, the precision of estimation can be maximized for certain values of the Unruh acceleration. We also investigate the contribution of the different parts of the Fisher information on the dynamics of the total Fisher information.