# 2$\Phi_{0}$-periodic magnetic interference in ballistic graphene Josephson junctions

## TL;DR

This study reveals unusual 2Φ₀-periodic interference patterns in ballistic graphene Josephson junctions near the Dirac point, suggesting possible topological effects or intrinsic properties of graphene affecting supercurrent behavior.

## Contribution

It reports the observation of anomalous 2Φ₀ periodicity in graphene Josephson junctions, challenging conventional understanding of supercurrent interference patterns.

## Key findings

- Standard Fraunhofer pattern at high doping
- Anomalous 2Φ₀ periodicity near the Dirac point
- Pattern persists with temperature and edge modifications

## Abstract

We investigate supercurrent interference patterns measured as a function of magnetic field in ballistic graphene Josephson junctions. At high doping, the expected $\Phi_{0}$-periodic "Fraunhofer" pattern is observed, indicating a uniform current distribution. Close to the Dirac point, we find anomalous interference patterns with an apparent 2$\Phi_{0}$ periodicity, similar to that predicted for topological Andreev bound states carrying a charge of $e$ instead of $2e$. This feature persists with increasing temperature, ruling out a non-sinusoidal current-phase relationship. It also persists in junctions in which sharp vacuum edges are eliminated. Our results indicate that the observed behavior may originate from an intrinsic property of ballistic graphene Josephson junctions, though the exact mechanism remains unclear.