The pairing symmetry of interacting Dirac fermions on the $\ensuremath{\pi}$-flux lattice is studied with the determinant quantum Monte Carlo and numerical linked-cluster expansion methods. The
s∗- (i.e., extended
s-) and
d-wave pairing symmetries, which are distinct in the conventional square lattice, are degenerate under the Landau gauge. We demonstrate that the dominant pairing channel at strong interactions is an unconventional
ds∗-wave phase consisting of alternating stripes of
s∗- and
d-wave phases. A complementary mean-field analysis shows that while the
s∗- and
d-wave symmetries individually have nodes in the energy spectrum, the
ds∗ channel is fully gapped. The results represent a new realization of pairing in Dirac systems, connected to the problem of chiral
d-wave pairing on the honeycomb lattice, which might be more readily accessed by cold-atom experiments.
The pairing symmetry of interacting Dirac fermions on the π-flux lattice is studied with the determinant quantum Monte Carlo and numerical linked-cluster expansion methods. The s*- (i.e., extended s-) and d-wave pairing symmetries, which are distinct in the conventional square lattice, are degenerate under the Landau gauge. We demonstrate that the dominant pairing channel at strong interactions is an unconventional ds*-wave phase consisting of alternating stripes of s*- and d-wave phases. A complementary mean-field analysis shows that while the s*- and d-wave symmetries individually have nodes in the energy spectrum, the ds* channel is fully gapped. The results represent a new realization of pairing in Dirac systems, connected to the problem of chiral d-wave pairing on the honeycomb lattice, which might be more readily accessed by cold-atom experiments.
A constrained path quantum Monte Carlo simulation is performed to investigate the superconducting pairing correlation in doped staggered-flux Hubbard model on a square lattice, which is an interesting platform to host Dirac fermions. For various electron fillings and interaction strengths, the [Formula: see text] pairing dominates over other pairing forms since its long-range correlation is larger over mostly distances. We deepen our study by including the nearest-neighbor interaction [Formula: see text] and found the [Formula: see text] pairing correlation is slightly suppressed by increasing [Formula: see text].