Effect of decoherence on the Berry phase of a spin-half in a rotating magnetic field

TL;DR

This paper studies how a bosonic environment influences the Berry phase of a spin-1/2 system in a rotating magnetic field, highlighting the impact of low-frequency quantum noise without relying on the Markovian approximation.

Contribution

It provides a non-Markovian analysis of decoherence effects on the Berry phase in a time-dependent magnetic field, emphasizing the role of low-frequency quantum noise.

Findings

Low-frequency quantum noise significantly alters the Berry phase.

High-frequency noise has minimal effect in the adiabatic limit.

Results are applicable to broader scenarios beyond the specific model.

Abstract

We investigate the decoherence effect of a bosonic bath on the Berry phase of a spin-1/2 in a time-dependent magnetic field, without making the Markovian approximation. A two-cycle process resulting in a pure Berry phase is considered. The low-frequency quantum noise significantly affects the Berry phase. In the adiabatic limit, the high-frequency quantum noise only has a small effect. The result is also valid in some more general situations.