Probing critical phenomena in open quantum systems using atom arrays

TL;DR

This paper demonstrates how a Rydberg quantum simulator can prepare and analyze critical ground states in open quantum systems, revealing universal power-law correlations and boundary effects in 1D and 2D lattices.

Contribution

It introduces a method to directly observe and extract universal scaling dimensions of critical states in open quantum systems using adiabatic preparation in atom arrays.

Findings

Successful adiabatic preparation of critical ground states in 1D and 2D lattices.

Direct measurement of power-law correlations and scaling dimensions.

Identification of distinct boundary universality classes in 2D.

Abstract

At continuous phase transitions, quantum many-body systems exhibit scale-invariance and complex, emergent universal behavior. Most strikingly, at a quantum critical point, correlations decay as a power law, with exponents determined by a set of universal scaling dimensions. Experimentally probing such power-law correlations is extremely challenging, owing to the complex interplay between decoherence, the vanishing energy gap, and boundary effects. Here, we employ a Rydberg quantum simulator to adiabatically prepare critical ground states of both a one-dimensional ring and a two-dimensional square lattice. By accounting for and tuning the openness of our quantum system, which is well-captured by the introduction of a single phenomenological length scale, we are able to directly observe power-law correlations and extract the corresponding scaling dimensions. Moreover, in two dimensions, we observe a decoupling between phase transitions in the bulk and on the boundary, allowing us to identify two distinct boundary universality classes. Our work demonstrates that direct adiabatic preparation of critical states in quantum simulators can complement recent approaches to studying quantum criticality using the Kibble-Zurek mechanism or digital quantum circuits.