Switchable superconducting quantum interferometers

Abstract

In a simple bilayer device structure, a ferromagnetic film spans a lithographically patterned superconducting loop. When the magnetization orientation is along the loop axis, magnetoquenched weak links are formed in each arm of the loop. Quantum interference effects are studied by applying a weak magnetic field perpendicular to the sample plane. Switching the magnetization between stable orientations parallel or perpendicular to the loop axis turns the interference ON or OFF, demonstrating a switchable superconducting quantum interference device.