Many-body localization from dynamical gauge fields

摘要

A recent experiment [C. Schweizer, F. Grusdt, M. Berngruber, L. Barbiero, E. Demler. N. Goldman, I. Bloch, and M. Aidelsburger, Nat. Phys. 15, 1168 (2019)] has realized a dynamical gauge system with a Z_2 gauge symmetry in a double-well potential. In this work we propose a method to generalize this model from a single double well to a one-dimensional chain. We show that although there are no disordered potentials in the original model, the phenomenon of many-body localization can occur. The key ingredient is that different symmetry sectors with different local gauge charges play the role of different disorder configurations, which becomes clear-after exactly mapping our model to a transverse Ising model in a random longitudinal field. We show that both the ergodic regime and the many-body localized regime exist in this model from four different metrics, which include level statistics, volume law versus area law of entanglement entropy of eigenstates, quench dynamics of entanglement entropy, and physical observables.