Surface Spectral Function of Momentum-dependent Pairing Potentials in a Topological Insulator: Application to Cu$_x$Bi$_2$Se$_3$

摘要

We propose three possible momentum-dependent pairing potentials for candidateof topological superconductor (for example Cu$_x$Bi$_2$Se$_3$), and calculatethe surface spectral function and surface density of state with these pairingpotentials. We find that the first two can give the same spectral functions asthe fully-gapped and node-contacted pairing potentials given in [Phys. Rev.Lett. 105, 097001], and that the third one can obtain topological non-trivialcase which exists flat Andreev bound state and preserves the $C_3$ rotationsymmetry. We hope our proposals and results be judged by future experiment.