Quantum Circuits Using the Disordered Superconductor WSi (Part II)

Kinetic inductance materials have been widely used in the superconducting detector community and are now applied in circuit QED, allowing for the implementation of distributed high inductance and highly nonlinear elements. However, devices based on such materials have not yet reached the simultaneous levels of high nonlinearity and low loss commonly achieved with Josephson junction-based devices. In this project, we aim to address this problem by optimizing devices based on WSi, an amorphous superconductor commonly used in single-photon detectors for its lack of grain boundaries and high-quality thin films.

In part two of this three-part talk, we focus on WSi nanowires. The application of high-kinetic inductance nanowires to superconducting qubits could lead to realization of weak-link junctions and quantum phase slip elements that further expand the parameters of intrinsically protected qubits. We present our design and characterization of these nanowire devices.