Real-time simulation of dissipation-driven quantum systems

TL;DR

This paper develops a real-time path integral approach to simulate dissipation-driven quantum systems, enabling efficient simulation of certain spin-1/2 systems by eliminating the sign problem through averaging over measurement results.

Contribution

It introduces a novel real-time path integral method for dissipation-driven quantum systems and demonstrates how averaging over measurements removes the sign problem for spin-1/2 systems.

Findings

Sign problem disappears when averaging over measurement results.

Efficient cluster algorithm enables simulation of specific quantum systems.

Method applies to dissipation-driven quantum dynamics.

Abstract

We set up a real-time path integral to study the evolution of quantum systems driven in real-time completely by the coupling of the system to the environment. For specifically chosen interactions, this can be interpreted as measurements being performed on the system. For a spin-1/2 system, in particular, when the measurement results are averaged over, the resulting sign problem completely disappears, and the system can be simulated with an efficient cluster algorithm.