Decoherence by a spin thermal bath: Role of the spin-spin interactions and initial state of the bath

TL;DR

This paper investigates how the structure and initial state of a spin-bath environment influence the decoherence of a central spin system, revealing that connectivity, coupling strength, and initial conditions qualitatively alter decay behaviors.

Contribution

It demonstrates the critical role of environment connectivity, coupling, and initial state in determining decoherence dynamics in spin systems.

Findings

Connectivity and coupling strength switch decoherence from Gaussian to exponential decay.

Initial environment state significantly affects decoherence behavior.

Decoherence dynamics depend on environment structure and initial conditions.

Abstract

We study the decoherence of two coupled spins that interact with a spin-bath environment. It is shown that the connectivity and the coupling strength between the spins in the environment are of crucial importance for the decoherence of the central system. For the anisotropic spin-bath, changing the connectivity or coupling strenghts changes the decoherence of the central system from Gaussian to exponential decay law. The initial state of the environment is shown to affect the decoherence process in a qualitatively significant manner.