SKM 2023 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 53: Graphene

TT 53.2: Vortrag

Donnerstag, 30. März 2023, 15:15–15:30, HSZ 204

Graphene superlattice due to twisted hexagonal boron nitride monolayers — •Ming-Hao Liu — Department of Physics, National Cheng Kung University, Tainan 70101, Taiwan

Stacking of two-dimensional (2D) materials of similar lattice structures on top of each other with a small twist angle leads to the so-called Moiré pattern due to the large-scale lattice inteference. When one of them is a conducting material such as graphene, the Moiré pattern serves as a large-scale periodic potential, turning the host conducting lattice into a superlattice, whose modified electronic properties can be seen in transport experiments and simulations. Graphene placed on a hexagonal boron nitride (hBN) layer is one of the best known graphene superlattices, while twisted bilayer graphene made of two monolayers of graphene is another example under intensive investigations during the past years. Twisted monolayers of hBN also form the Moiré pattern, yet its effect on transport properties of neighboring graphene is less known. Here, we consider graphene put on monolayers of twisted hBN (thBN), and perform quantum transport simulations considering the effect of the charge-polarized superlattice potential [1]. Due to the exceptionally long Moiré wavelength of the twisted hBN, multiple satellite Dirac points emerge in the transmission spectrum within the experimentally accessible range of the carrier density. Possible experiments confirming the model of graphene on thBN as well as further exploring novel transport behaviors due to the thBN will be discussed.
[1] C. R. Woods et al., Nat. Commun. 12, 347 (2021)