Fragmented quantum phases in anti-blockade regime of Rydberg atom array

TL;DR

This paper explores how anti-blockade conditions in a Rydberg atom array lead to complex quantum phases characterized by Hilbert space fragmentation, revealing new non-thermal dynamical behaviors and phase transitions.

Contribution

It uncovers parameter-dependent Hilbert space fragmentation and dynamical phases in Rydberg arrays, highlighting the role of multi-path interference and cascaded excitations.

Findings

Identification of distinct non-equilibrium dynamical phases

Demonstration of transition from thermalization to fragmentation

Discovery of secondary fragmentation enabled by local constraints

Abstract

In this Letter, we report a parameter-dependent Hilbert space fragmentation in a one-dimensional Rydberg atom array under anti-blockade conditions. We identify distinct non-equilibrium dynamical phases and show that their quasi-periodic behavior arises from the interplay of multi-path interference and multi-photon cascaded excitations, reflecting fundamental differences in state connectivity and effective dimensionality. By constructing a complete phase diagram, we reveal the transition from thermalization to fragmentation, and further demonstrate a secondary fragmentation process enabled by local constraints. Our results highlight the potential of anti-blockade mechanisms for programmable non-thermal dynamics in many-body systems.