Berlin 2024 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 53: 2D Materials and Heterostructures: (Twisted) Bilayers (joint session HL/TT)
HL 53.9: Talk
Friday, March 22, 2024, 12:00–12:15, EW 201
Gate screening of Coulomb interactions in Bernal bilayer graphene — •Isabell Weimer1, Anna Seiler1, Dong Zhao2, Jurgen Smet2, and R. Thomas Weitz1 — 11st Institute of Physics, Faculty of Physics, Georg-August-University Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany — 2MPI for Solid State Research, Heisenbergstraße 1, 70569 Stuttgart, Germany
Measurements on dual gated, hexagonal Boron Nitride (hBN) encapsulated Bernal bilayer graphene samples, have revealed a complex phase space for Bernal bilayer graphene, including numerous Stoner metals, a correlated insulator consistent with a Wigner-Hall crystal [1] and superconducting behavior [2].
We have investigated the influence of the gate induced Coulomb interaction screening [3] on the appearance of previously reported correlated phases in gated Bernal bilayer graphene devices, using the thickness of the dielectric hBN spacing layers as variable parameter. In direct comparison of devices studied here, which are characterized by a comparably thin h-BN layer, with the data of Seiler et. al. , we observed behavior, which is supportive of an effectively lowered magnitude of Coulomb interactions. Additionally, three features in the transport data were identified, which could potentially be indicative of phases, not reported in [1] and [2].
References: [1] Seiler, Anna M., et al. Nature 608.7922 (2022): 298-302. [2] Zhou, Haoxin, et al. Science 375.6582 (2022): 774-778. [3] Kim, Minsoo, et al. Nature communications 11.1 (2020): 2339.