Proximity-effect-induced superconductivity in Bi2Te3/FeSe0.5Te0.5 superlattices

The topological-insulator/superconductor heterostructure is predicted to offer an opportunity to investigate the proximity effect in condensed matter systems. Here, we construct a well-ordered Bi2Te3/FeSe0.5Te0.5 superlattice structure on TiO2-SrTiO3 substrate by pulsed laser deposition, and investigate its superconducting property induced by the proximity effect. Based on the electrical transport measurements, Cooper pairs in superconducting FeSe0.5Te0.5 layers can be introduced into the surface states of Bi2Te3 layers, and so induce superconductivity of the entire Bi2Te3/FeSe0.5Te0.5 superlattice. The superconducting prop erties in the superlattices such as the superconducting critical temperature anisotropy gamma, critical current density J(c), and flux pinning mechanism depend strongly on the thicknesses of FeSe0.5Te0.5 and Bi2Te3 layers. The thicker FeSe0.5Te0.5 layer and thinner Bi2Te3 layer are beneficial for the performance of superconductivity. Our experimental results provide a pathway to studying the mechanism of proximity effect at the interfaces between superconductor and topological insulator. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The superconducting property induced by the proximity effect was observed in a topological-insulator/superconductor heterostructure, and it was found that the superconducting properties depend on the thicknesses of the layers.