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arXiv · 2211.01020

High magnetic field stability in a planar graphene-NbSe$_2$ SQUID

Ayelet Zalic·Takashi Taniguchi·Kenji Watanabe·Snir Gazit·Hadar Steinberg
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Abstract

Thin NbSe$_2$ retains superconductivity at high in-plane magnetic field up to 30 T. In this work we construct an atomically thin, all van der Waals SQUID, in which current flows between NbSe$_2$ contacts through two parallel graphene weak links. This fully planar device remains uniquely stable at high in-plane field. This enables tracing the evolution of the critical current interference patterns as a function of the field up to 4.5 T, allowing nm-scale sensitivity to deviations from a perfect atomic plane. We present numerical methods to retrieve asymmetric current distributions J$_0$ from measured interference maps, and suggest a new application of the dual junction geometry to probe the current density in the absence of phase information. The interference maps exhibit a striking field-driven transition, indicating a redistribution of supercurrents to narrow channels. Our results suggest the existence of a preferred conductance channel with an exceptional stability to in-plane magnetic field.

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Ayelet Zalic, Takashi Taniguchi, Kenji Watanabe, Snir Gazit, Hadar Steinberg. 2022-11-02. High magnetic field stability in a planar graphene-NbSe$_2$ SQUID. https://doi.org/10.1021/acs.nanolett.3c01552

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