Probing spontaneously symmetry-broken phases with spin-charge separation through noise correlation measurements

TL;DR

This paper introduces a novel method using noise correlation measurements after ballistic expansion to identify different spontaneously symmetry-broken phases with spin-charge separation in quantum systems, demonstrated on a 1D Fermi-Hubbard model.

Contribution

The authors propose and validate a new technique based on noise correlators to distinguish SSB phases, offering an alternative to traditional local order parameter measurements.

Findings

Noise correlators can differentiate SSB phases with spin-charge separation.

The method accurately identifies charge density wave, bond-ordering wave, and antiferromagnetic phases.

Numerical results confirm the effectiveness of the approach on a 1D extended Fermi-Hubbard model.

Abstract

Spontaneously symmetry-broken (SSB) phases are locally ordered states of matter characterizing a large variety of physical systems. Because of their specific ordering, their presence is usually witnessed by means of local order parameters. Here, we propose an alternative approach based on statistical correlations of noise after the ballistic expansion of an atomic cloud. We indeed demonstrate that probing such noise correlators allows one to discriminate among different SSB phases characterized by spin-charge separation. As a particular example, we test our prediction on a 1D extended Fermi-Hubbard model, where the competition between local and nonlocal couplings gives rise to three different SSB phases: a charge density wave, a bond-ordering wave, and an antiferromagnet. Our numerical analysis shows that this approach can accurately capture the presence of these different SSB phases, thus representing an alternative and powerful strategy to characterize strongly interacting quantum matter.