Theoretical proposal to obtain strong Majorana evidence from scanning tunneling spectroscopy of a vortex with a dissipative environment

Abstract

It is predicted that a vortex in a topological superconductor contains a Majorana zero mode (MZM). The confirmative Majorana signature, i.e., the 2e2/h quantized conductance, however, is easily sabotaged by unavoidable interruptions, e.g., instrument broadening, non-Majorana signal, and extra particle channels. To avoid these interruptions, we propose to obtain strong Majorana evidence following our novel Majorana hunting protocol that relies on dissipation introduced by disorders at, e.g., the sample-substrate interface. Within this protocol, we highlight three features, each of which alone can provide a strong evidence to identify MZM. First, dissipation suppresses a finite-energy Caroli-de Gennes-Matricon (CdGM) conductance peak into a valley, while it does not split MZM zero-bias conductance peak (ZBCP). Second, we predict a dissipation-dependent scaling feature of the ZBCP. Third, the introduced dissipation manifests the MZM signal by suppressing nontopological CdGM modes. Importantly, the observation of these features does not require a quantized conductance value 2e2/h.