# Field-Effect Controllable Metallic Josephson Interferometer

## TL;DR

This paper presents titanium-based, gate-tunable Josephson interferometers that enable independent control of junctions, demonstrating full modulation of supercurrent and phase, with potential applications in quantum computing and sensing.

## Contribution

The work introduces a monolithic titanium-based interferometer with independent voltage control of junctions, advancing the scalability and tunability of superconducting devices.

## Key findings

- Full control of switching current amplitude across a wide temperature range
- Gate-biasing can suppress total supercurrent below single junction critical current
- A theoretical model explains gate-induced phase fluctuations

## Abstract

Gate-tunable Josephson junctions (JJs) are the backbone of superconducting classical and quantum computation. Typically, these systems exploit low charge concentration materials, and present technological diffculties limiting their scalability. Surprisingly, electric field modulation of supercurrent in metallic wires and JJs has been recently demonstrated. Here, we report the realization of titanium-based monolithic interferometers which allow tuning both JJs independently via voltage bias applied to capacitively-coupled electrodes. Our experiments demonstrate full control of the amplitude of the switching current (IS) and of the superconducting phase across the single JJ in a wide range of temperatures. Astoundingly, by gate-biasing a single junction the maximum achievable total IS suppresses down to values much lower than the critical current of a single JJ. A theoretical model including gate-induced phase fluctuations on a single junction accounts for our experimental findings. This class of quantum interferometers could represent a breakthrough for several applications such as digital electronics, quantum computing, sensitive magnetometry and single-photon detection.