Confined and Deconfined Phases of Qubit Regularized Lattice Gauge Theories

TL;DR

This paper introduces qubit-regularized lattice gauge theories that exhibit both confined and deconfined phases, and explores their phase transitions and potential continuum limits using Monte Carlo simulations.

Contribution

The authors construct sign-problem-free qubit-regularized Hamiltonian lattice gauge theories in the MDTN basis, revealing both phases and analyzing phase transitions.

Findings

Finite-temperature phase transitions match SU(N) universality classes

Models exhibit both confined and deconfined phases

Second-order quantum phase transitions may enable continuum limits

Abstract

We construct simple qubit-regularized Hamiltonian lattice gauge theories formulated in the monomer--dimer--tensor-network (MDTN) basis that are free of sign problems in the pure gauge sector. These models naturally realize both confined and deconfined phases. Using classical Monte Carlo methods, we investigate the associated finite-temperature phase transitions and show that they exhibit the expected universality classes of conventional SU(N) lattice gauge theories in various spacetime dimensions. Furthermore, we argue that second-order quantum phase transitions separating the confined and deconfined phases are likely to exist. Such critical points would provide a nonperturbative route to defining continuum limits of qubit-regularized gauge theories, potentially allowing Yang--Mills theory and related continuum gauge theories to emerge from finite-dimensional lattice constructions.