Quantum Superinductor with Tunable Non-Linearity

TL;DR

This paper presents a tunable superinductor made from Josephson junctions with high impedance and nonlinearity, enabling advanced quantum computing and precision measurement applications.

Contribution

The authors demonstrate a nanoscale Josephson junction ladder superinductor with tunable inductance and nonlinearity controlled by a magnetic field.

Findings

Rabi decay time exceeds 1 microsecond

Impedance surpasses resistance quantum

Tunable nonlinearity enables new quantum functionalities

Abstract

We report on the realization of a superinductor, a dissipationless element whose microwave impedance greatly exceeds the resistance quantum. The design of the superinductor, implemented as a ladder of nanoscale Josephson junctions, enables tuning of the inductance and its nonlinearity by a weak magnetic field. The Rabi decay time of the superinductor-based qubit exceeds 1 microsecond. The high kinetic inductance and strong nonlinearity offer new types of functionality, including the development of qubits protected from both flux and charge noises, fault tolerant quantum computing, and high-impedance isolation for electrical current standards based on Bloch oscillations.