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arXiv · 2106.08405

Probing two-electron multiplets in bilayer graphene quantum dots

Samuel Möller·Luca Banszerus·Angelika Knothe·Corinne Steiner·Eike Icking·Stefan Trellenkamp·Florian Lentz·Kenji Watanabe·Takashi Taniguchi·Leonid Glazman·Vladimir Fal'ko·Christian Volk·Christoph Stampfer
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Abstract

We report on finite bias spectroscopy measurements of the two-electron spectrum in a gate defined bilayer graphene (BLG) quantum dot for varying magnetic fields. The spin and valley degree of freedom in BLG give rise to multiplets of 6 orbital symmetric and 10 orbital anti-symmetric states. We find that orbital symmetric states are lower in energy and separated by $\approx 0.4 - 0.8$ meV from orbital anti-symmetric states. The symmetric multiplet exhibits an additional energy splitting of its 6 states of $\approx 0.15 - 0.5$ meV due to lattice scale interactions. The experimental observations are supported by theoretical calculations, which allow to determine that inter-valley scattering and 'current-current' interaction constants are of the same magnitude in BLG.

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Samuel Möller, Luca Banszerus, Angelika Knothe, Corinne Steiner, Eike Icking, Stefan Trellenkamp, Florian Lentz, Kenji Watanabe, Takashi Taniguchi, Leonid Glazman, Vladimir Fal'ko, Christian Volk, Christoph Stampfer. 2022-01-10. Probing two-electron multiplets in bilayer graphene quantum dots. https://doi.org/10.1103/physrevlett.127.256802

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