Real-time simulation of non-equilibrium transport of magnetization in large open quantum spin systems driven by dissipation

TL;DR

This paper uses quantum Monte Carlo to simulate the real-time non-equilibrium transport of magnetization in large dissipative quantum spin systems, revealing diffusion behavior in driven, strongly correlated environments.

Contribution

It introduces a method to study non-equilibrium magnetization transport in large open quantum spin systems with dissipation conserving magnetization, combining numerical simulation with analytical diffusion models.

Findings

Magnetization transport follows a diffusion equation.

Dissipative processes can be modeled analytically.

Simulation results match theoretical diffusion predictions.

Abstract

Using quantum Monte Carlo, we study the non-equilibrium transport of magnetization in large open strongly correlated quantum spin $\frac{1}{2}$ systems driven by purely dissipative processes that conserve the uniform or staggered magnetization. We prepare both a low-temperature Heisenberg ferromagnet and an antiferromagnet in two parts of the system that are initially isolated from each other. We then bring the two subsystems in contact and study their real-time dissipative dynamics for different geometries. The flow of the uniform or staggered magnetization from one part of the system to the other is described by a diffusion equation that can be derived analytically.