Entanglement dynamics and ergodicity breaking in a quantum cellular automaton

TL;DR

This paper explores how ergodicity breaking and nonlocal entanglement manifest in a quantum cellular automaton, revealing potential applications for quantum computation through the control of chaotic states.

Contribution

It demonstrates that ergodicity breaking extends to chaotic states in a quantum cellular automaton, driven by chiral quasiparticle excitations that propagate entanglement.

Findings

Ergodicity breaking persists in chaotic states of the automaton.

Nonlocal entanglement is observed in nonthermal chaotic states.

Chiral quasiparticles control the dynamical breaking of ergodicity.

Abstract

Ergodicity breaking is observed in the blockade regime of Rydberg atoms arrays, in the form of low entanglement eigenstates known as scars, which fail to thermalize. The signature of these states persists in periodically driven systems, where they coexist with an extensive number of chaotic states. Here we investigate a quantum cellular automaton based on the classical rule that updates a site if its two neighbors are in the lower state. We show that the breaking of ergodicity extends to chaotic states. The dynamical breaking of ergodicity is controlled by chiral quasiparticle excitations which propagate entanglement. Evidence of nonlocal entanglement is found, showing that these nonthermal chaotic states may be useful to quantum computation.