Broad and colossal edge supercurrent in Dirac semimetal Cd3As2 Josephson junctions

Abstract

Edge supercurrent has attracted great interest recently due to its crucial role in achieving and manipulating topological superconducting states. Proximity-induced superconductivity has been realized in quantum Hall and quantum spin Hall edge states, as well as in higher-order topological hinge states. Non-Hermitian skin effect, the aggregation of non-Bloch eigenstates at open boundaries, promises an abnormal edge channel. Here we report the observation of broad edge supercurrent in Dirac semimetal Cd₃As₂-based Josephson junctions. The as-grown Cd₃As₂ nanoplates are electron-doped by intrinsic defects, which enhance the non-Hermitian perturbations. The superconducting quantum interference indicates edge supercurrent with a width of ~1.6 μm and a magnitude of ~1 μA at 10 mK. The wide and large edge supercurrent is inaccessible for a conventional edge system and suggests the presence of non-Hermitian skin effect. A supercurrent nonlocality is also observed. The interplay between band topology and non-Hermiticity is beneficial for exploiting exotic topological matter.

The non-Hermitian skin effect, or localization of eigenstates at the boundary of a non-Hermitian system, has been intensively studied. Chu et al. observe a large and wide edge supercurrent in the Dirac semimetal Cd₃As₂-based Josephson junctions, which is consistent with the non-Hermitian skin effect.