Quantum annealing via environment-mediated quantum diffusion

TL;DR

This paper demonstrates that environment-mediated quantum diffusion near a quantum critical point can significantly enhance the efficiency of open-system quantum annealing, outperforming traditional methods.

Contribution

It introduces a novel quantum annealing mechanism based on excitation diffusion and shows its advantages over closed-system annealing and Glauber dynamics.

Findings

Diffusion-mediated quantum annealing can be faster than closed-system annealing.

Excitation diffusion slows near the quantum critical point, leading to effective freezing.

Spatial correlations emerge, aiding in efficient annealing.

Abstract

We show that quantum diffusion near the quantum critical point can provide a highly very efficient mechanism of open-system quantum annealing. It is based on the diffusion-mediated recombination of excitations. For an Ising spin chain coupled to a bosonic bath, excitation diffusion in a transverse field sharply slows down as the system moves away from the quantum critical region. This leads to spatial correlations and effective freezing of the excitation density. We find that obtaining an approximate solution via the diffusion-mediated quantum annealing can be faster than via closed-system quantum annealing or Glauber dynamics.