A metastable superconducting qubit

TL;DR

This paper introduces a novel superconducting qubit design using a tunable RF-SQUID and nanowire inductors, aiming to significantly enhance qubit lifetime and fidelity by reducing environmental electromagnetic coupling.

Contribution

The proposed design achieves a metastable state with greatly reduced electromagnetic coupling, potentially leading to longer qubit lifetimes and higher fidelity operations.

Findings

Design reduces electromagnetic coupling to environment

Potential for qubit lifetime increase by orders of magnitude

Enables higher fidelity quantum operations

Abstract

We propose a superconducting qubit design, based on a tunable RF-SQUID and nanowire kinetic inductors, which has a dramatically reduced transverse electromagnetic coupling to its environment, so that its excited state should be metastable. If electromagnetic interactions are in fact responsible for the current excited-state decay rates of superconducting qubits, this design should result in a qubit lifetime orders of magnitude longer than currently possible. Furthermore, since accurate manipulation and readout of superconducting qubits is currently limited by spontaneous decay, much higher fidelities may be realizable with this design.