Engineered thermalization and cooling of quantum many-body systems

TL;DR

This paper presents a method to engineer thermal states in quantum many-body systems using driven, dissipative ancilla spins, with potential applications in quantum simulation hardware.

Contribution

It introduces a scheme for thermalizing quantum many-body systems via ancilla pseudospins with periodic energy modulation, supported by a theoretical framework and numerical validation.

Findings

Effective thermalization achieved under specific modulation conditions

Conditions for true thermal states as dynamical fixed points identified

Numerical simulations confirm protocol feasibility

Abstract

We develop a scheme for engineering genuine thermal states in analog quantum simulation platforms by coupling local degrees of freedom to driven, dissipative ancilla pseudospins. We demonstrate the scheme in a many-body quantum spin lattice simulation setting. A Born-Markov master equation describing the dynamics of the many-body system is developed, and we show that if the ancilla energies are periodically modulated, with a carefully chosen hierarchy of timescales, one can effectively thermalize the many-body system. Through analysis of the time-dependent dynamical generator, we determine the conditions under which the true thermal state is an approximate dynamical fixed point for general system Hamiltonians. Finally, we evaluate the thermalization protocol through numerical simulation and discuss prospects for implementation on current quantum simulation hardware.