Berlin 2024 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 53: 2D Materials and Heterostructures: (Twisted) Bilayers (joint session HL/TT)

HL 53.1: Vortrag

Freitag, 22. März 2024, 09:30–09:45, EW 201

Lattice relaxation, electronic structure and continuum model for twisted bilayer MoTe2 — •Ning Mao¹, Cheng Xu^2,3, Jiangxu Li², Ting Bao³, Peitao Liu⁴, Yong Xu³, Claudia Felser¹, Liang Fu⁵, and Yang Zhang^2,6 — ¹Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany — ²Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996, USA — ³Department of Physics, Tsinghua University, Beijing 100084, China — ⁴Institute of Metal Research, Chinese Academy of Sciences, 110016 Shenyang, China — ⁵Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA — ⁶Min H. Kao Department of Electrical Engineering and Computer Science, University of Tennessee, Knoxville, Tennessee 37996, USA

Our study delves into the effect of lattice relaxation on the moiré band structures of twisted bilayer MoTe2, implemented by large-scale first-principles calculations and transfer learning neural network. Throughout our study, we have incorporated two van der Waals correction methods: the Grimme D2 method and a density-dependent energy correction. Notably, the latter method demonstrates a continuous evolution of bandwidth with respect to twist angles. Our findings reveal the critical role of in-plane lattice displacements, which generate substantial pseudomagnetic fields, reaching up to 250 T. Building on these insights, we have developed a comprehensive continuum model with a single set of parameters for a wide range of twist angles, providing a useful starting point for many-body simulation.

Keywords: large-scale first-principles calculations; machine learning; moiré heterostructure; continuum model; lattice relaxation effect