Lattice Defects in Rydberg Atom Arrays

TL;DR

This paper explores how geometric defects in one-dimensional Rydberg atom arrays affect their quantum critical behavior, revealing how different kink types influence system order, localization, and correlation functions, with implications for experimental fidelity.

Contribution

It provides a detailed analysis of the effects of geometric defects on Rydberg atom arrays at and away from criticality, highlighting the role of kinks and defect control for accurate quantum simulations.

Findings

Site-centered kinks can effectively break the array at the kink position.

Bond-centered kinks lead to intermediate-coupling fixed points.

Defects induce localization-delocalization transitions of domain walls.

Abstract

Rydberg atom arrays have become a key platform for studying quantum many-body systems. In these setups, defects arise naturally due to various imperfections and can significantly modify the theoretical predictions compared to an ideal model. Here, we investigate the impact of geometric defects in the simplest situation -- a one-dimensional Rydberg atom array, both at and away from its emergent Ising criticality. In the presence of defects, we demonstrate that relevant physical quantities can be extracted from one-point correlation functions. At the critical point, we show that different types of kinks yield distinct outcomes corresponding to their respective spatial-internal symmetries: site-centered kinks can effectively break the array at the kink position regardless of the kink angle, while bond-centered kinks lead to interesting intermediate-coupling fixed points. In the latter case, due to a special renormalization group flow trajectory, the whole system can appear ordered if the system is not large enough. Additionally, away from criticality, the bond-centered kink induces a localization-delocalization transition of the domain wall, characteristic of quantum wetting. These findings highlight the utility of kinks as experimental probes and stress the importance of controlling defects so that experimental observations remain faithful to the pristine model.