In search of exotic pairing in the Hubbard model: Many-body computation and quantum gas microscopy
Year: 2026
Type: article
Abstract: Finite-momentum pairing, exemplified by Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) states, represents a paradigmatic form of unconventional superfluidity driven by Fermi-surface mismatch, but its detection in two-dimensional systems has remained elusive. Here we study a doped, spin-imbalanced attractive Hubbard model using a combined experimental and computational approach, based on quantum gas microscopy and constrained-path auxiliary-field quantum Monte Carlo, with direct comparisons showing quantitative agreement for short-range correlations at experimentally accessible temperatures. We identify broad regimes in density and magnetization where FFLO correlations emerge, and establish their finite-temperature evolution, with clear signatures of finite-momentum pairing already appearing at experimentally accessible temperatures. Spin-XY correlations are identified as a robust, directly measurable proxy for FFLO physics. Quantitative characterizations are obtained on the temperature dependence of a variety of observables and correlations, which elucidate the interplay of pairing with competing orders.
Institutions: Max Planck Society, Max Planck Institute for the Physics of Complex Systems, Flatiron Institute, MIT-Harvard Center for Ultracold Atoms, Massachusetts Institute of Technology, Northwest University, Northwest University, Peng Huanwu Center for Fundamental Theory, Institute of Modern Physics, Shaanxi Key Laboratory for Theoretical Physics Frontiers
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
OpenAlex ID: W4416712260