Markovianity of an emitter coupled to a structured spin chain bath

TL;DR

This paper investigates the conditions under which a spin-1/2 subsystem coupled to a structured spin chain bath exhibits Markovian dynamics, revealing regimes of Markovianity and non-Markovianity through numerical simulations.

Contribution

It provides the first detailed analysis of Markovianity in a spin chain bath, identifying regimes where Markovian descriptions are valid despite many-body interactions.

Findings

Regimes where the subsystem dynamics are Markovian.

Coupling at the edge leads to different behavior than coupling at the center.

Numerical simulations characterize divisibility and Markovianity.

Abstract

We analyze the dynamics of a spin 1/2 subsystem coupled to a spin chain. We simulate numerically the full quantum many-body system for various sets of parameters and initial states of the chain, and characterize the divisibility of the subsystem dynamics, i.e. whether it is Markovian and can be described by a (time dependent) master equation. We identify regimes in which the subsystem admits such Markovian description, despite the many-body setting, and provide insight about why the same is not possible in other regimes. Interestingly, coupling the subsystem at the edge, instead of the center, of the chain gives rise to qualitatively distinct behavior.