Spin bath interactions effects on the geometric phase

TL;DR

This paper investigates how a spin bath environment influences the geometric phase of a spin-1/2 particle, highlighting the effects of decoherence and parameter dependence in open quantum systems.

Contribution

It provides a detailed analysis of the geometric phase under nonunitary evolution due to spin bath interactions, including validity of perturbative methods.

Findings

Decoherence significantly alters the geometric phase.

Parameter variations affect the phase deviation.

Perturbative approximation has a limited range of validity.

Abstract

We calculate the geometric phase of a spin-1/2 particle coupled to an external environment comprising N spin-1/2 particle in the framework of open quantum systems. We analyze the decoherence factor and the deviation of the geometric phase under a nonunitary evolution from the one gained under an unitary one. We show the dependence upon the system's and bath's parameter and analyze the range of validity of the perturbative approximation. Finally, we discuss the implications of our results.