Vortex state of topological superconductorCuxBi2Se3

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 Hc1. 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 Hc1 may be observed. The observation (or nonobservation) of it will narrow down the mechanism of the superconductivity in CuxBi2Se3