Monolithic hybrid quantum dot devices in superconducting twisted bilayer graphene

Alexandra Mestre-Torà; Marta Perego; Clara Galante Agero; Takashi Taniguchi; Kenji Watanabe; Thomas Ihn; Klaus Ensslin; Artem O. Denisov

arXiv · 2606.14685

Monolithic hybrid quantum dot devices in superconducting twisted bilayer graphene

Alexandra Mestre-Torà·Marta Perego·Clara Galante Agero·Takashi Taniguchi·Kenji Watanabe·Thomas Ihn·Klaus Ensslin·Artem O. Denisov

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Abstract

Gate-tunable superconductivity in magic-angle twisted bilayer graphene (MATBG) has enabled the realization of superconducting devices, such as Josephson junctions, within a single crystal. This interface-free platform provides a reconfigurable and scalable architecture that overcomes limitations of conventional superconducting-semiconducting systems. Incorporating single-electron control enables access to regimes in which flat-band superconductivity competes with strong Coulomb repulsion, providing a platform for studying correlated physics phenomena. Here, we report a new class of quantum devices that combines electrostatic confinement with tunable superconductivity in a monolithic MATBG architecture. Within a single device, we demonstrate two complementary hybrid systems: superconducting islands and proximitized quantum dots. The superconducting island exhibits $2e$-periodic transport, indicating a well-defined gap protected against quasiparticle poisoning. The proximitized quantum dot hosts subgap Andreev states together with a strongly parity-modulated supercurrent.

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Alexandra Mestre-Torà, Marta Perego, Clara Galante Agero, Takashi Taniguchi, Kenji Watanabe, Thomas Ihn, Klaus Ensslin, Artem O. Denisov. 2026-06-12. Monolithic hybrid quantum dot devices in superconducting twisted bilayer graphene. https://arxiv.org/abs/2606.14685

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