Energy distribution controlled ballistic Josephson junction

TL;DR

This paper demonstrates how applying a control voltage to a graphene-based Josephson junction allows precise tuning of supercurrent by manipulating Andreev states, revealing two distinct regimes of electron distribution.

Contribution

It introduces a novel method to control supercurrent in ballistic graphene Josephson junctions via a transverse normal channel, enabling tunable superconducting circuits.

Findings

Supercurrent can be tuned by control voltage in a four-terminal graphene Josephson junction.

Two regimes identified: double-step distribution and hot-electron distribution.

Potential for designing highly controllable superconducting quantum devices.

Abstract

We report an experimental study on the tuning of supercurrent in a ballistic graphene-based Josephson junction by applying a control voltage to a transverse normal channel. In this four-terminal geometry, the control voltage changes the occupation of Andreev states in the Josephson junction, thereby tuning the magnitude of the supercurrent. As a function of gate voltage, we find two different regimes characterized by a double-step distribution and a hot-electron distribution, respectively. Our work opens new opportunities to design highly controllable Josephson junctions for tunable superconducting quantum circuits.