Intrinsic supercurrent non-reciprocity coupled to the crystal structure of a van der Waals Josephson barrier

Jae-Keun Kim; Kun-Rok Jeon; Pranava K. Sivakumar; Jaechun Jeon; Chris Koerner; Georg Woltersdorf; Stuart S. P. Parkin

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arXiv · 2303.13049

Intrinsic supercurrent non-reciprocity coupled to the crystal structure of a van der Waals Josephson barrier

Jae-Keun Kim·Kun-Rok Jeon·Pranava K. Sivakumar·Jaechun Jeon·Chris Koerner·Georg Woltersdorf·Stuart S. P. Parkin

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Abstract

Non-reciprocal electronic transport in a spatially homogeneous system arises from the simultaneous breaking of inversion and time-reversal symmetries. Superconducting and Josephson diodes, a key ingredient for future non-dissipative quantum devices, have recently been realized. Only a few examples of a vertical superconducting diode effect have been reported and its mechanism, especially whether intrinsic or extrinsic, remains elusive. Here we demonstrate a substantial supercurrent non-reciprocity in a van der Waals vertical Josephson junction formed with a Td-WTe2 barrier and NbSe2 electrodes that clearly reflects the intrinsic crystal structure of Td-WTe2. The Josephson diode efficiency increases with the Td-WTe2 thickness up to critical thickness, and all junctions, irrespective of the barrier thickness, reveal magneto-chiral characteristics with respect to a mirror plane of Td-WTe2. Our results, together with the twist-angle-tuned magneto-chirality of a Td-WTe2 double-barrier junction, show that two-dimensional materials promise vertical Josephson diodes with high efficiency and tunability.

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Jae-Keun Kim, Kun-Rok Jeon, Pranava K. Sivakumar, Jaechun Jeon, Chris Koerner, Georg Woltersdorf, Stuart S. P. Parkin. 2023-03-23. Intrinsic supercurrent non-reciprocity coupled to the crystal structure of a van der Waals Josephson barrier. https://arxiv.org/abs/2303.13049

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