Superconducting Contact and Quantum Interference Between Two-Dimensional van der Waals and Three-Dimensional Conventional Superconductors

TL;DR

This paper demonstrates a method to create zero-resistance superconducting contacts between 2D NbSe2 and 3D aluminum, enabling Josephson junctions with potential applications in hybrid quantum circuits.

Contribution

It introduces a novel fabrication technique for 2D-3D superconducting contacts and models supercurrent flow, advancing hybrid superconducting quantum circuit development.

Findings

Successful creation of zero-resistance 2D-3D superconducting contacts.

Large-area Josephson junctions with 2D-3D interfaces.

Good agreement between Ginzburg-Landau model and experimental results.

Abstract

Two-dimensional (2D) transition-metal dichalcogenide superconductors have unique and desirable properties for integration with conventional superconducting circuits. However, fully superconducting contact must be made between the 2D material and three-dimensional (3D) superconductors in order to employ the standard microwave drive and readout of qubits in such circuits. Here, we present a method for creating zero-resistance contacts between 2D NbSe$_2$ and 3D aluminum that behave as Josephson junctions (JJs) with large effective areas compared to 3D-3D JJs. We present a model for the supercurrent flow in a 2D-3D superconducting structure by numerical solution of the Ginzburg-Landau equations and find good agreement with experiment. These results demonstrate a crucial step towards a new generation of hybrid superconducting quantum circuits.