Vortex state of topological superconductorCuxBi2Se3

Abstract

The electron pairing in the topological superconductor has been predicted to be spin-triplet pairing with odd parity. If the superconducting carries have a magnetic moment, the magnetization arising from it reduces the repulsive interaction between the vortices, thus the vortex density drastically increases in the region above the lower critical magnetic field ${H}_{c1}$. The comparison of the theoretical calculation with the experimental result by Das et al. [Phys. Rev. B 83, 220513(R) (2011)] indicates that the magnetization is small, suggesting that it is not a spin-triplet superconductor. The theory suggests that if the nonzero magnetization arises from the supercurrent carriers a hysteresis in the magnetization curve around ${H}_{c1}$ may be observed. The observation (or nonobservation) of it will narrow down the mechanism of the superconductivity in ${\mathrm{Cu}}_{x}{\mathrm{Bi}}_{2}{\mathrm{Se}}_{3}$.