Majorana Fermions and Exotic Surface Andreev Bound States in Topological Superconductors: Application to CuₓBi₂Se₃

Abstract

The recently discovered superconductor CuₓBi₂Se₃ is a candidate for three-dimensional time-reversal-invariant topological superconductors, which are predicted to have robust surface Andreev bound states hosting massless Majorana fermions. In this work, we analytically and numerically find the linearly dispersing Majorana fermions at k=0, which smoothly evolve into a new branch of gapless surface Andreev bound states near the Fermi momentum. The latter is a new type of Andreev bound states resulting from both the nontrivial band structure and the odd-parity pairing symmetry. The tunneling spectra of these surface Andreev bound states agree well with a recent point-contact spectroscopy experiment [ S. Sasaki et al. Phys. Rev. Lett. 107 217001 (2011)] and yield additional predictions for low temperature tunneling and photoemission experiments.