In-plane and out-of-plane magnetic field driven Josephson diode effect in magic-angle twisted four-layer graphene

Marta Perego; Sayan Banerjee; Mohamad Abu El Hija; Clara Galante Agero; Alexandra Mestre-Torà; Giovanni Zhang; Takashi Taniguchi; Kenji Watanabe; Mathias S. Scheurer; Thomas Ihn; Klaus Ensslin

arXiv · 2606.21229

In-plane and out-of-plane magnetic field driven Josephson diode effect in magic-angle twisted four-layer graphene

Marta Perego·Sayan Banerjee·Mohamad Abu El Hija·Clara Galante Agero·Alexandra Mestre-Torà·Giovanni Zhang·Takashi Taniguchi·Kenji Watanabe·Mathias S. Scheurer·Thomas Ihn·Klaus Ensslin

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Abstract

The superconducting diode effect offers a powerful probe into the fundamental symmetries of quantum materials. Recent studies on twisted graphene diodes have predominantly focused on bilayer or trilayer systems under out-of-plane magnetic fields. Here, we demonstrate both out-of-plane and in-plane driven Josephson diode effects in a magic-angle twisted four-layer graphene junction, i.e., an even number of layers. We observe the emergence of a diode effect at zero out-of-plane field, tuned by an increasing in-plane magnetic field. This result points to the presence of strong in-plane orbital coupling, which is highly sensitive to the specific layer parity of the structure. Our findings provide experimental insights into the symmetry-breaking mechanisms of even-layer twisted graphene, establishing in-plane magnetic fields as a vital tool for unravelling their microscopic properties.

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Marta Perego, Sayan Banerjee, Mohamad Abu El Hija, Clara Galante Agero, Alexandra Mestre-Torà, Giovanni Zhang, Takashi Taniguchi, Kenji Watanabe, Mathias S. Scheurer, Thomas Ihn, Klaus Ensslin. 2026-09-14. In-plane and out-of-plane magnetic field driven Josephson diode effect in magic-angle twisted four-layer graphene. https://arxiv.org/abs/2606.21229

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