Berezinskii-Kosterlitz-Thouless transition in the time-reversal-symmetric Hofstadter-Hubbard model

Abstract

Assuming that two-component Fermi gases with opposite artificial magnetic fields on a square optical lattice are well-described by the so-called time-reversal-symmetric Hofstadter-Hubbard model, we explore the thermal superfluid properties along with the critical Berezinskii-Kosterlitz-Thouless (BKT) transition temperature in this model over a wide-range of its parameters. In particular, since our self-consistent BCS-BKT approach takes the multi-band butterfly spectrum explicitly into account, it unveils how dramatically the inter-band contribution to the phase stiffness dominates the intra-band one with an increasing interaction strength for any given magnetic flux.

9 pages with 3 figures; to appear in PRA

References in corpus (2)

• Band geometry, Berry curvature and superfluid weight
• Hofstadter-Hubbard model with opposite magnetic fields: Bardeen-Cooper-Schrieffer pairing and superfluidity in the nearly flat butterfly bands

Cited by in corpus (7)

• Extracting quantum-geometric effects from Ginzburg-Landau theory in a multiband Hubbard model
• Anomalous Coherence Length in Superconductors with Quantum Metric
• Cooper pairing, flat-band superconductivity and quantum geometry in the pyrochlore-Hubbard model
• Superfluid stiffness for the attractive Hubbard model on a honeycomb optical lattice
• Coherence length and quantum geometry in a dilute flat-band superconductor
• Structure factors and quantum geometry in multiband BCS superconductors
• Theory of Hofstadter Superconductors