Dynamics of quantum Fisher information in a squeezed thermal bath

TL;DR

This paper investigates how quantum Fisher information evolves for a qubit in a squeezed thermal bath, identifying optimal conditions and comparing different environmental regimes to enhance parameter estimation robustness.

Contribution

It introduces a detailed analysis of quantum Fisher information dynamics in various environmental regimes and highlights the robustness of parameter estimation against squeezing effects.

Findings

Optimal initial states maximize Fisher information

Fisher information varies with environment type (ohmic, sub-ohmic, super-ohmic)

Parameter estimation is robust against squeezing

Abstract

In this paper, the dynamics of quantum Fisher information of a qubit interacting with a squeezed thermal environment are studied. The optimal initial state of the qubit, the temperature of the environment, and the interaction time, which maximize quantum Fisher information are obtained. Based on the ohmicity of the environment, we compare the dynamics of quantum Fisher information in ohmic, sub-ohmic, and super-ohmic regimes of the environment. Moreover, it is shown that the precise estimation of parameters is robust against squeezing.