Superconductivity and Majorana Fermions in Doped Topological Insulators(Research)

Abstract

Doped topological insulators show a variety of superconductivity including topological ones due to their peculiar electronic states and orbital degrees of freedom. We find a transition of energy dispersion of surface Andreev bound states on topological insulators, i.e., Lifshitz transition. This causes anomalous enhancement of tunneling conductance in junction of a normal metal and superconducting topological insulator, which suggests that a recent discovered superconducting topological insulator Cu_xBi_2Se_3 is a three-dimensional topological superconductor.