Novel anisotropic spin singlet pairings in Cu${}_x$Bi${}_2$Se${}_3$ and Bi${}_2$Te${}_3$

Abstract

Possible anisotropic spin singlet pairings in Bi${}_2$X${}_3$ (X is Se or Te) are studied. Among six pairings compatible with the crystal symmetry, two novel pairings show nontrivial surface Andreev bound states, which form flat bands and could produce zero bias conductance peak in measurements like point contact spectroscopy. By considering purely repulsive short range Coulomb interaction as the pairing mechanism, the dominant superexchange terms are all antiferromagnetic, which would usually favor spin singlet pairing in Bi${}_2$X${}_3$. Mean field analyses show that the interorbital pairing interaction favors a mixed spatial-parity anisotropic pairing state, and one pairing channel with zero energy surface states has a sizable component. The results provide important new information for future experiments.

13 pages, 2 figures, 3 tables

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Cited by in corpus (7)

• Evidence of nodes in the order parameter of the superconducting doped topological insulator Nb${}_x$Bi${}_2$Se${}_3$ via penetration depth measurements
• Superconducting doped topological materials
• Topological Phase Transitions and a Two-Dimensional Weyl Superconductor in a Half-Metal/Superconductor Heterostructure
• Nematic superconductivity in Cu${}_x$Bi${}_2$Se${}_3$: The surface Andreev bound states
• Searching for two-dimensional Weyl superconductors in heterostructures
• Effective low energy theory for surface Andreev bound states of superconducting phases in generalized Bernevig-Hughes-Zhang models
• Possible two-component pairings in electron-doped Bi${}_2$Se${}_3$ based on a tight-binding model