Observation of superconductivity in 3D Dirac semimetal Cd3As2 crystal

TL;DR

This study reports the observation of unconventional p-wave like superconductivity in the 3D Dirac semimetal Cd3As2, suggesting it could be a candidate topological superconductor capable of hosting Majorana modes.

Contribution

First experimental evidence of superconductivity in Cd3As2 via point contact measurements, revealing potential topological superconductivity in a 3D Dirac semimetal.

Findings

Detection of zero bias conductance peak (ZBCP)

Observation of double conductance peaks (DCPs)

Indication of p-wave like unconventional superconductivity

Abstract

Lately, the three-dimensional (3D) Dirac semimetal, which possesses 3D linear dispersion in electronic structure as a bulk analogue of graphene, has generated widespread interests in both material science and condensed matter physics. Very recently, crystalline Cd3As2 has been proposed and proved to be one of 3D Dirac semimetals which can survive in atmosphere. Here, by controlled point contact (PC) measurement, we observe the exotic superconductivity around point contact region on the surface of Cd3As2 crystal. The observation of zero bias conductance peak (ZBCP) and double conductance peaks (DCPs) symmetric to zero bias further reveal p-wave like unconventional superconductivity in Cd3As2 quantum matter. Considering the topological property of the 3D Dirac semimetal, our findings may indicate that the Cd3As2 crystal under certain conditions is a candidate of the topological superconductor, which is predicted to support Majorana zero modes or gapless Majorana edge/surface modes in the boundary depending on the dimensionality of the material.