Systematic construction of quantum many-body scars in frustrated Rydberg arrays

TL;DR

This paper introduces a graph-theoretic framework to identify quantum many-body scars in frustrated Rydberg arrays, revealing mechanisms for nonthermal dynamics beyond bipartite lattices.

Contribution

It develops a systematic method to find scarred states on arbitrary lattices and uncovers two mechanisms for scarring in frustrated Rydberg systems.

Findings

Predicts two distinct scar mechanisms: type-I and type-II.

Demonstrates exponential family of scarred trajectories on hexagonal lattices.

Establishes scarring as a generic feature beyond one dimension.

Abstract

Quantum many-body scars in Rydberg atom arrays have thus far only been observed on bipartite lattices, leaving open the question of whether and how they survive frustration, and what the appropriate initial states are that lead to nonthermal dynamics. We introduce a graph-theoretic framework to find suitable candidates for scarring on arbitrary lattices. Our framework predicts two distinct mechanisms: type-I scars generalize the bipartite case by using locally entangled states to overcome mild frustration, while type-II scars exploit strong frustration to pin part of the lattice, leaving the remainder to oscillate freely. We numerically demonstrate both mechanisms and uncover an exponential family of scarred trajectories on the hexagonal lattice that can encode information protected from thermalization. Our results establish scarring as a generic feature of Rydberg systems beyond one dimension and provide an experimentally accessible route to systematically probing non-thermal dynamics in quantum simulators.