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DS: Fachverband Dünne Schichten

DS 5: 2D Materials and their Heterostructures II: Graphene and Graphene Containing Heterostructures

DS 5.6: Talk

Tuesday, March 19, 2024, 11:00–11:15, A 053

Extended Hubbard model describing small multi-dot arrays in bilayer graphene — •Angelika Knothe¹ and Guido Burkard² — ¹Institut für Theoretische Physik, Universität Regensburg, D-93040 Regensburg, Germany — ²Department of Physics, University of Konstanz, 78457 Konstanz, Germany

Confined quantum dot states are attractive for various applications, from qubits to store quantum information to simulating exotic quantum phases. Here, 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 constant by, e.g., gates and a magnetic field. For half-filling and large valley splittings, we derive and parametrize an effective Heisenberg model for the quantum dot spins.

Keywords: Bilayer graphene; Quantum dots; Nanostructures