The Superconducting Quantum Interference Proximity Transistor (SQUIPT)

Abstract

In this article we review the basic theoretical properties of a hybrid superconducting interferometer which exploits the phase dependence of the density of states of a metallic nanowire placed in good electric contact with a superconductor to achieve high sensitivity to magnetic flux. The operation of a prototype structure based on this principle, the superconducting quantum interference proximity transistor (SQUIPT), has been recently reported. Limited power dissipation joined with the opportunity to access single-spin detection make this interferometer attractive for the investigation of the switching dynamics of individual magnetic nanoparticles. The noise behavior of the device is presented as well, where the feasibility of this structure as a single-spin detector is also briefly addressed. In the final part we present the response of a real SQUIPT device.