Universal conductance scaling of Andreev reflections using a dissipative probe

Abstract

The Majorana search is caught up in an extensive debate about the false-positive signals from non-topological Andreev bound states (ABSs). We introduce a remedy using the dissipative probe to generate electron-boson interaction. We theoretically show that the interaction-induced renormalization leads to significantly distinct universal zero-bias conductance behaviors, i.e. distinct characteristic power-law in temperature, for different types of Andreev reflections, which shows a sharp contrast to that of a Majorana zero mode. Various specific cases have been studied, including the cases that two charges involved in an Andreev reflection process maintain/lose coherence, and the cases for multiple ABSs with or without a Majorana present. A transparent list of conductance features in each case is provided to help distinguishing the observed subgap states in experiments, which also promotes the identification of Majorana zero modes.