Superfluid stiffness for the attractive Hubbard model on a honeycomb optical lattice

Abstract

In addition to the conventional contribution that is directly controlled by the single-particle energy spectrum, the superfluid phase stiffness of a two-component Fermi gas has a geometric contribution that is governed by the quantum metric of the honeycomb's band structure. Here, we take both contributions into account, and construct phase diagrams for the critical superfluid transition temperature as a function of the chemical potential, particle filling, onsite interaction and next-nearest-neighbor hopping. Our theoretical approach is based on a self-consistent solution of the BCS mean-field theory for the stationary Cooper pairs and the universal BKT relation for the phase fluctuations.

7 pages with 4 figures; to appear in PRA

References in corpus (3)

• Band geometry, Berry curvature and superfluid weight
• BCS-BEC crossover on the two-dimensional honeycomb lattice
• Berezinskii-Kosterlitz-Thouless transition in the time-reversal-symmetric Hofstadter-Hubbard model

Cited by in corpus (8)

• Origin of flat-band superfluidity on the Mielke checkerboard lattice
• Pairs, trimers and BCS-BEC crossover near a flat band: the sawtooth lattice
• Quantum geometric superfluid weight in multiband superconductors: A microscopic interpretation
• Predictive power of the Berezinskii-Kosterlitz-Thouless theory based on Renormalization Group throughout the BCS-BEC crossover in 2D superconductors
• Emergence of charge density wave and superconducting phase transitions through Lorentz-invariant interactions in the Haldane-Hubbard model
• Revisiting flat band superconductivity: dependence on minimal quantum metric and band touchings
• Connection between the semiconductor--superconductor transition and the spin-polarized superconducting phase in the honeycomb lattice
• Theory of Hofstadter Superconductors