Patterning Superconductivity in a Topological Insulator

TL;DR

This paper demonstrates a method to pattern superconductivity in topological insulator nanostructures by selective palladium doping, enabling the creation of customizable superconducting circuits for quantum computing applications.

Contribution

It introduces a novel technique for directly patterning superconductivity in Bi2Se3 nanostructures through targeted Pd doping and annealing, facilitating circuit design in topological materials.

Findings

Superconductivity can be selectively patterned in Bi2Se3 nanostructures.

Doping with Pd induces superconducting regions with variable transition characteristics.

Pd remains localized, allowing arbitrary-shaped superconducting circuits.

Abstract

While topological superconductors are predicted to provide building blocks for fault-tolerant quantum computing, one of the remaining challenges is to find a convenient experimental platform that would allow patterning of circuits. We find that superconductivity can be patterned directly into Bi$_2$Se$_3$ nanostructures by selective doping with palladium (Pd). Superconducting regions are defined by depositing Pd on top of the nanostructures using electron beam lithography, followed by in-situ annealing. Electrical transport measurements at low temperatures show either partial or full superconducting transition, depending on the doping conditions. Structural characterization techniques indicate that Pd remains localized in the targeted areas, making it possible to pattern superconducting circuits of arbitrary shapes in this topological material.