Theory of lattice relaxation in homobilayer twist moirés

ORAL

Abstract

Lattice relaxation in moiré materials can strongly modify the electronic moiré bands. This is especially true in moirés made from transition metal dichalcogenides (TMDs) for which relaxation is an order of magnitude stronger compared to graphene moirés. Here we present analytical results for relaxation in homobilayer twist moirés based on symmetry constraints and continuum elasticity. We focus on twist moirés with D6 and D3 stacking symmetry such as parallel and antiparallel stacked homobilayer TMDs, respectively. In particular, we consider both the perturbative regime (large twist angles) and the regime of domain formation (tiny twist angles). Our results agree well with numerical solutions and molecular dynamics simulations. Finally, we demonstrate how our theory yields expressions for the strain-induced pseudo gauge fields and modified moiré potentials in the presence of lattice relaxation.

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Publication: Mohammed M. Al Ezzi, Gayani N. Pallewela, Christophe De Beule, E. J. Mele, and Shaffique Adam, Analytical Model for Atomic Relaxation in Twisted Moiré Materials (arXiv:2401.00498)

Christophe De Beule, Gayani N. Pallewela, Liangtao Peng, Mohammed M. Al Ezzi, E. J. Mele, and Shaffique Adam, Domain formation in twisted transition metal dichalcogenide bilayers (in preparation)

Christophe De Beule, Liangtao Peng, E. J. Mele, and Shaffique Adam, Lattice relaxation in homobilayer moirés (in preparation)

Presenters

  • Christophe De Beule

    University of Pennsylvania

Authors

  • Christophe De Beule

    University of Pennsylvania

  • Gayani Nadeera Pallewela

    Natl Univ of Singapore

  • Mohammed M Al Ezzi

    Harvard University and National University of Singapore, Natl Univ of Singapore

  • Eugene John Mele

    University of Pennsylvania

  • Shaffique Adam

    Washington University, Washington University in St. Louis, Washington University St Louis