Current Amplification with Vertical Josephson Interferometers

TL;DR

This paper explores the use of vertical Josephson interferometers with small loop inductances to achieve high current amplification, discussing their operation, advantages, and potential applications.

Contribution

It introduces a novel vertical Josephson interferometer design capable of large current gains and compares its performance to traditional planar devices.

Findings

Vertical interferometers can achieve high current gain due to small loop inductance.

Theoretical analysis demonstrates advantages over planar interferometers.

Potential applications include sensitive superconducting electronic devices.

Abstract

It has long been recognized that a control current $I_a$ injected into the section of a two-junction superconducting quantum interference device (SQUID) is able to produce a change of its critical current $I_c$, so that a current gain $g=|dI_c/dI_a|$ can be identified. We investigate the circumstances under which large gains can be achieved by using vertical Josephson interferometers which are characterized by small loop inductances. We discuss the theory of operation of such a novel device, its performances and its advantages with respect to planar interferometers used in the previous works. Two potential applications are addressed.