Time-Evolving Weiss Fields in the Stochastic Approach to Quantum Spins

TL;DR

This paper introduces a method to extend simulation times for non-equilibrium quantum spin systems by dynamically adjusting the Gaussian noise mean in stochastic differential equations, improving real-time dynamics analysis.

Contribution

It presents a novel approach to optimize stochastic simulations of quantum spins through dynamic noise mean shifts, enhancing simulation stability and duration.

Findings

Extended simulation times in 1D and 2D quantum spin systems.

Dynamic noise mean adjustment reduces stochastic fluctuations.

Connection established with gauge-P drift gauges.

Abstract

We investigate non-equilibrium quantum spin systems via an exact mapping to stochastic differential equations. This description is invariant under a shift in the mean of the Gaussian noise. We show that one can extend the simulation time for real-time dynamics in one and two dimensions by a judicious choice of this shift. This can be updated dynamically in order to reduce the impact of stochastic fluctuations. We discuss the connection to drift gauges in the gauge-P literature.