Stabilizing coherence with nested environments: a numerical study using kicked Ising models

TL;DR

This study numerically investigates how a far environment coupled to a near environment can slow decoherence in a tripartite quantum spin system, confirming that increased coupling can protect quantum coherence.

Contribution

It provides numerical evidence that coupling a far environment to a near environment can slow decoherence in a quantum chaotic spin system, extending previous theoretical results.

Findings

Increased near-far environment coupling slows decoherence.

Coupling protects internal entanglement.

Results hold across various coupling strengths and configurations.

Abstract

We study a tripartite system of coupled spins, where a first set of one or two spins is our central system which is coupled to another set considered, the near environment, in turn coupled to the third set, the far environment. The dynamics considered are those of a generalized kicked spin chain in the regime of quantum chaotic dynamics. This allows to test recent results that suggest that the presence of a far environment, coupled to the near environment, slows decoherence of the central system. After an extensive numerical study, we confirm previous results for extreme values and special cases. In particular, under a wide variety of circumstances an increasingly large coupling between near and far environment, slows decoherence, as measured by purity, and protects internal entanglement.