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arXiv · 2504.12252

Electric field tunable spin-orbit gap in a bilayer graphene/WSe$_{2}$ quantum dot

Hubert Dulisch·David Emmerich·Eike Icking·Katrin Hecker·Samuel Möller·Leonie Müller·Kenji Watanabe·Takashi Taniguchi·Christian Volk·Christoph Stampfer
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Abstract

We report on the investigation of proximity-induced spin-orbit coupling (SOC) in a heterostructure of bilayer graphene (BLG) and tungsten diselenide (WSe$_2$). A BLG quantum dot (QD) in the few-particle regime acts as a sensitive probe for induced SOC. Finite bias and magnetotransport spectroscopy measurements reveal a significantly enhanced SOC that decreases with the applied displacement field, distinguishing it from pristine BLG. Furthermore, our measurements demonstrate a reduced valley $g$-factor at larger displacement fields, consistent with a weaker lateral confinement of the QD. Our findings show evidence of the influence of WSe$_2$ across BLG layers, driven by reduced real-space confinement and increased layer localization of the QD states on the BLG layer distant to the WSe$_2$ at higher displacement fields. This study demonstrates the electrostatic tunability of the spin-orbit gap in BLG/WSe$_2$ heterostructures, which is especially relevant for the field of spintronics and future spin qubit control in BLG QDs.

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Hubert Dulisch, David Emmerich, Eike Icking, Katrin Hecker, Samuel Möller, Leonie Müller, Kenji Watanabe, Takashi Taniguchi, Christian Volk, Christoph Stampfer. 2025-05-31. Electric field tunable spin-orbit gap in a bilayer graphene/WSe$_{2}$ quantum dot. https://doi.org/10.1021/acs.nanolett.5c02229

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