Revealing Intrinsic Superconductivity of the Nb/BiSbTe₂Se Interface

Abstract

Typically, topological superconductivity is reachable via proximity effect by a direct deposition of superconductor (S) on top of a topological insulator (TI) surface. Here, the double critical current in the Josephson junctions based on the topological insulator is observed in the fabricated planar Superconducting Quantum Interference Devicea. By measuring critical currents as a function of temperature and magnetic field, it is shown that the second critical current stems from the intrinsic superconductivity of the S–TI interface, which is supported by the modified Resistively Shunted Junction model and Transmission Electron Microscopy studies. This complex structure of the interface should be taken into account when the technological process involves Ar‐plasma cleaning.

Contribution of Processes in SN Electrodes to the Transport Properties of SN-N-NS Josephson Junctions

“…Therefore, the fact that the experimental dependence coincides with the theoretical dependence for purely ballistic contacts does not provide a clear indication as to which of the structures (SNS or SINIS) was actually studied. Thus, in [ 45 ], the presence of two critical currents was detected in the structures obtained by sputtering of Nb on top of Fe-doped BiSbTe 2 Se flake. According to the authors, the existence of the second critical current results from the intrinsic superconductivity of the Nb–Fe-doped BiSbTe 2 Se interface.…”

Effect of the Post‐Annealing Temperature on the Interfacial Reaction Between a High TC Superconductor and Topological Insulator

“…Recently, some papers have reported this effect at the heterojunction between the superconductor and TI. [ 4 ] These phenomena enable the development of quantum computers, spintronics, and novel optoelectronics. [ 5,6 ] However, only a few studies have reported the “superconducting proximity effect” on the heterojunction between HTS and TI.…”