Probing quantum floating phases in Rydberg atom arrays

TL;DR

This paper experimentally observes the quantum floating phase in Rydberg atom arrays, revealing incommensurate order and domain wall proliferation, advancing understanding of phase transitions in quantum many-body systems.

Contribution

First experimental detection of the quantum floating phase in large Rydberg atom arrays, demonstrating incommensurate order and phase transition signatures.

Findings

Observation of domain walls leading to floating phase formation

Fourier analysis shows incommensurate wave order

Wave vectors approach a continuum with increasing system size

Abstract

The floating phase, a critical incommensurate phase, has been theoretically predicted as a potential intermediate phase between crystalline ordered and disordered phases. In this study, we investigate the different quantum phases that arise in ladder arrays comprising up to 92 neutral-atom qubits and experimentally observe the emergence of the quantum floating phase. We analyze the site-resolved Rydberg state densities and the distribution of state occurrences. The site-resolved measurement reveals the formation of domain walls within the commensurate ordered phase, which subsequently proliferate and give rise to the floating phase with incommensurate quasi-long-range order. By analyzing the Fourier spectra of the Rydberg density-density correlations, we observe clear signatures of the incommensurate wave order of the floating phase. Furthermore, as the experimental system sizes increase, we show that the wave vectors approach a continuum of values incommensurate with the lattice. Our work motivates future studies to further explore the nature of commensurate-incommensurate phase transitions and their non-equilibrium physics.