Experimental studies of the topological superconductor Cu xBi2Se3

Abstract

CuxBi2Se3 was recently elucidated to be the first example of a time-reversal-invariant topological superconductor characterized by the gapless surface quasiparticle states consisting of helical Majorana fermions. The evidence for topological superconductivity in CuxBi2Se3 was obtained by the point-contact spectroscopy that indirectly detected the itinerant massless Majorana state on the surface. In this paper, we show new point-contact spectroscopy data which supplement the previous conclusion. We also present the anisotropic normal-state resistivity data for superconducting samples of CuxBi2Se3 which strongly suggest that not only the effective mass but also the scattering rate is anisotropic in this material by a factor of ∼3. © Published under licence by IOP Publishing Ltd.