Hybrid Quantum Interferometer in Bifurcation Mode as a Latching Quantum Readout

TL;DR

This paper introduces a hybrid quantum interferometer operating in a bifurcation mode, serving as a latching magnetometer for sensitive flux measurements and qubit readout with minimal back-action.

Contribution

It presents a novel hybrid quantum device that functions as a latching magnetometer, enabling straightforward flux detection and qubit measurement.

Findings

Demonstrated operation in a bi-stable, latching mode

Achieved sensitive flux change detection

Suitable for low-back-action qubit readout

Abstract

We have developed a new type of magnetometer consisting of a Hybrid Quantum Interference Device (HyQUID) that is set in a bi-stable state. We demonstrate its operation in a latching mode that can be employed to measure small changes in the applied flux. The device can be used to probe the flux state of a superconducting circuit using straightforward electrical resistance measurements, making it suitable as a simple qubit readout with low back-action.