Entanglement dynamics and ergodicity breaking in a quantum cellular\n automaton

Abstract

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