Entanglement evolution of a spin chain bath in driving the decoherence of a coupled quantum spin

TL;DR

This paper studies how entanglement in a spin chain bath affects the decoherence of a coupled electron spin, revealing periodic and decaying behaviors that distinguish coherence preservation from decoherence.

Contribution

It provides a detailed analysis of entanglement dynamics in a spin chain bath and its role in electron spin decoherence, highlighting the significance of bath entanglement in coherence phenomena.

Findings

Spin bath entanglement distinguishes zero-coherence states.

Periodic entanglement correlates with coherence-preserving phases.

Infinite chain limit shows zero-value coherence evolution.

Abstract

For an electron spin in coupling with an interacting spin chain via hyperfine-type interaction, we investigate the dynamical evolutions of the pairwise entanglement of the spin chain and a correlation function joined the electron spin with a pair of chain spins in correspondence to the electron spin coherence evolution. Both quantities manifest a periodic and a decaying evolution. The entanglement of the spin bath is significant in distinguishing the zero-coherence status exhibited in periodic and decoherence evolutions of the electron spin. The periodical concurrence evolution of the spin bath characterizes the whole system in a coherence-preserving phase, particularly for the case that the associated periodic coherence evolution is predominated by zero-value in the infinite chain-length limit, which was often regarded as the realization of decoherence.