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arXiv · 2401.09898

Extended Hubbard model describing small multi-dot arrays in bilayer graphene

Angelika Knothe·Guido Burkard
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Abstract

We set up and parametrize a Hubbard model for interacting quantum dots in bilayer graphene and study double dots as the smallest multi-dot system. We demonstrate the tunability of the spin and valley multiplets, Hubbard parameters, and effective exchange interaction by electrostatic gate potentials and the magnetic field. Considering both the long- and short-range Coulomb interaction, we map out the various spin and valley multiplets and calculate their energy gaps for different dot sizes and inter-dot separations. For half-filling and large valley splittings, we derive and parametrize an effective Heisenberg model for the quantum dot spins.

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Angelika Knothe, Guido Burkard. 2024-01-18. Extended Hubbard model describing small multi-dot arrays in bilayer graphene. https://doi.org/10.1103/physrevb.109.245401

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