Pairing symmetry in BiS${}_2-$based superconductors

Abstract

The possible pairing symmetries for BiS${}_2-$based superconductors is investigated by using a minimal two-orbital model with onsite and nearest-neighbor intraorbital attractions $V_0$ and $V_1$, respectively. By using the mean-field approximation and solving the self-consistent equations, the phase diagram of the pairing symmetry is obtained. It is shown that the model allows three possible pairing symmetries, depending on the values of $V_0$ and $V_1$: the isotopic $s-$wave pairing [${\Delta }_{\mathbf{k}}={\Delta }_s$], the anisotropic $s-$wave pairing [${\Delta }_{\mathbf{k}}={\Delta }_s+\frac{{\Delta }_{xs}}{2}(\cos k_x+\cos k_y)$] and the $d-$wave pairing [${\Delta }_{\mathbf{k}}=\frac{{\Delta }_d}{2}(\cos k_x-\cos k_y)$]. Furthermore the density of states for these pairing symmetries exhibit different behaviors which can be used to distinguish them.

Cited by in corpus (1)

• Evidence for Fully Gapped Strong Coupling S-wave Superconductivity in Bi4O4S3