Simulated quantum annealing as a simulator of non-equilibrium quantum dynamics

Abstract

Simulated quantum annealing based on the path-integral Monte Carlo is one of the most common tools to simulate quantum annealing on the classical hardware. Nevertheless, it is in principle highly non-trivial whether this classical algorithm can correctly reproduce the quantum dynamics of quantum annealing, particularly in the diabatic regime. We study this problem numerically through the generalized Kibble-Zurek mechanism of defect distribution in the simplest ferromagnetic onedimensional transverse-field Ising model with and without coupling to the environment. It is found that simulated quantum annealing reproduces some, but not all, of the properties of the defect distribution in the short-time region. The results suggest the necessity to exert a fair amount of caution in using simulated quantum annealing to study the detailed quantitative aspects of the dynamics of quantum annealing.