Unconventional early-time relaxation in the Rydberg chain

TL;DR

This paper investigates the unique early-time relaxation behavior of special initial states in Rydberg atom chains, revealing how quantum many-body scars influence decay rates and providing experimental avenues for detection.

Contribution

It demonstrates that the initial-state survival probability decay rate is governed by quantum many-body scars and explores effects of Hamiltonian deformations on relaxation dynamics.

Findings

Survival probability decays at a characteristic rate linked to scars

Deformations show behavior consistent with integrable and ergodic limits

Early relaxation signatures can be experimentally measured

Abstract

We show that unconventional relaxation dynamics of special initial states in one-dimensional arrays of Rydberg atoms produce non-generic decay of the initial-state survival probability (SP) at very early times. Using the PXP hamiltonian as a minimal model of the Rydberg blockade, we prove that the early-time SP for states exhibiting quantum many-body scarring (QMBS) decays at a characteristic rate, whose finite-size scaling is determined solely by scars. We numerically investigate the effects of both revival-enhancing and ergodicity-restoring deformations of the PXP hamiltonian and find results consistent with the limiting cases of integrable and ergodic dynamics, respectively. We moreover argue that such unconventional early relaxation of scarred initial states is characteristic of a whole class of QMBS models. Since the SP can be easily measured experimentally, our findings enable us to probe the presence of scars at time scales much shorter than that of thermalization.