Markovian and Non-Markovian dynamics in the one-dimensional transverse-field XY model

TL;DR

This paper investigates how the dynamics of a spin chain in a transverse magnetic field transition between Markovian and non-Markovian regimes, revealing critical points where information flow and Loschmidt-echo behavior change.

Contribution

It demonstrates how anisotropy and magnetic field induce dynamical transitions between Markovian and non-Markovian behavior in a quantum spin chain.

Findings

Isotropic interaction leads to Markovian dynamics.

Anisotropy induces non-Markovian behavior.

Critical points show non-analyticities in Loschmidt-echo rate.

Abstract

We consider an anisotropic spin-1/2 XY Heisenberg chain in the presence of a transverse magnetic field. Selecting the nearest neighbor pair spins as an open quantum system, the rest of the chain plays the role of the structured environment. In fact, the aforementioned system is used as a quantum probe signifying nontrivial features of the environment with which is interacting. We use a general measure that is based on the trace distance for the degree of non-Markovian behavior in open quantum systems. The witness of non-Markovianity takes on nonzero values whenever there is a flow of information from the environment back to the open system. We have shown that the dynamics of the system with isotropic Heisenberg interaction is Markovian. A dynamical transition into the non-Markovian regime is observed as soon as the anisotropy, {\gamma}, is applied. At the Ising value of the anisotropy {\gamma} = 1.0, all the information flows back from the environment to the system. The additional dynamical transition from the non-Markovian to the Markovian is obtained by applying the transverse magnetic field. In addition, we have focused on the time evolution of the Loschmidtecho return rate function. It is found that a non-analyticity can be seen in the time evolution of the Loschmidt-echo return rate function exactly at the critical points where a dynamical transition from the Markovian to the non-Markovian occurs.