Driving quantum many-body scars in the PXP model

TL;DR

This paper investigates how periodic driving influences quantum many-body scars in the PXP model, revealing new regimes and mechanisms for enhancing and stabilizing quantum revivals in Rydberg atom systems.

Contribution

It provides a detailed analysis of driving-induced scar enhancement, introduces a toy model for scar dynamics, and demonstrates stabilization of revivals via inhomogeneous driving.

Findings

Periodic modulation creates multiple scar regimes.

A toy model accurately describes scar dynamics.

Inhomogeneous driving stabilizes revivals from arbitrary states.

Abstract

Periodic driving has been established as a powerful technique for engineering novel phases of matter and intrinsically out-of-equilibrium phenomena such as time crystals. Recent work by Bluvstein et al. [Science 371, 1355 (2021)] has demonstrated that periodic driving can also lead to a significant enhancement of quantum many-body scarring, whereby certain non-integrable systems can display persistent quantum revivals from special initial states. Nevertheless, the mechanisms behind driving-induced scar enhancement remain poorly understood. Here we report a detailed study of the effect of periodic driving on the PXP model describing Rydberg atoms in the presence of a strong Rydberg blockade - the canonical static model of quantum many-body scarring. We show that periodic modulation of the chemical potential gives rise to a rich phase diagram, with at least two distinct types of scarring regimes that we distinguish by examining their Floquet spectra. We formulate a toy model, based on a sequence of square pulses, that accurately captures the details of the scarred dynamics and allows for analytical treatment in the large-amplitude and high-frequency driving regimes. Finally, we point out that driving with a spatially inhomogeneous chemical potential allows to stabilize quantum revivals from arbitrary initial states in the PXP model, via a mechanism similar to prethermalization.