Quantum Computing Universal Thermalization Dynamics in a (2+1)D Lattice Gauge Theory

TL;DR

This paper demonstrates the use of a digital quantum computer with trapped ions to study thermalization and quantum chaos in a 2+1D lattice gauge theory, revealing universal features of entanglement dynamics.

Contribution

It introduces a method to simulate and analyze thermalization in a lattice gauge theory using quantum computers, highlighting entanglement's role and universal chaos signatures.

Findings

Universal early-time signals for quantum chaos observed

Efficient learning of non-equilibrium states via randomized measurements

Quantum computers can study thermalization in complex gauge theories

Abstract

Simulating non-equilibrium phenomena in strongly-interacting quantum many-body systems, including thermalization, is a promising application of near-term and future quantum computation. By performing experiments on a digital quantum computer consisting of fully-connected optically-controlled trapped ions, we study the role of entanglement in the thermalization dynamics of a $Z_2$ lattice gauge theory in 2+1 spacetime dimensions. Using randomized-measurement protocols, we efficiently learn a classical approximation of non-equilibrium states that yields the gap-ratio distribution and the spectral form factor of the entanglement Hamiltonian. These observables exhibit universal early-time signals for quantum chaos, a prerequisite for thermalization. Our work, therefore, establishes quantum computers as robust tools for studying universal features of thermalization in complex many-body systems, including in gauge theories.