Deconfined quantum criticality on a triangular Rydberg array

TL;DR

This paper demonstrates that deconfined quantum critical points can be realized and studied in a Rydberg atom system on a triangular lattice, combining theoretical predictions with numerical confirmation and experimental proposals.

Contribution

It provides a field-theoretical analysis and numerical evidence for DQCPs in Rydberg arrays, and suggests experimental methods to observe the emergent U(1) symmetry.

Findings

Predicted critical exponents for phase transitions in Rydberg arrays.

Confirmed the emergence of a conformal field theory with U(1) symmetry near criticality.

Proposed experimental detection of U(1) symmetry in finite tweezer arrays.

Abstract

Fluctuations can drive continuous phase transitions between two distinct ordered phases -- so-called deconfined quantum critical points (DQCPs) -- which lie beyond the Landau-Ginzburg-Wilson paradigm. Despite several theoretical predictions over the past decades, experimental evidence of DQCPs remains elusive. We show that a DQCP can be explored in a system of Rydberg atoms arranged on a triangular lattice and coupled through van der Waals interactions. Specifically, we investigate the nature of the phase transition between two ordered phases at 1/3 and 2/3 Rydberg excitation density, which were recently probed experimentally in [P. Scholl et al., Nature 595, 233 (2021)]. Using a field-theoretical analysis, we predict both the critical exponents for infinitely long cylinders of increasing circumference and the emergence of a conformal field theory near criticality showing an enlarged U(1) symmetry -- a signature of DQCPs -- and confirm these predictions numerically. Finally, we extend these results to ladder geometries and show how the emergent U(1) symmetry could be probed experimentally using finite tweezer arrays.