General relation between stacking order and Chern index: A topological map of minimally twisted bilayer graphene

Theil S, Fleischmann M, Gupta R, Rost F, Wullschläger F, Sharma S, Meyer B, Shallcross S (2021)

Publication Type: Journal article

Publication year: 2021

Journal

Physical Review B American Physical Society

Book Volume: 104

Journal Issue: 12

DOI: 10.1103/PhysRevB.104.125412

Abstract

We derive a general relation between the stacking vector u describing the relative shift of two layers of bilayer graphene and the Chern index. We find C = nu(1 - sign(vertical bar V-AB vertical bar - vertical bar V-BA vertical bar)), where nu is a valley index and vertical bar V-alpha beta vertical bar the absolute value of the u dependent stacking potentials that uniquely determine the interlayer interaction; AA stacking plays no role in the topological character. With this expression we show that while ideal and relaxed minimally twisted bilayer graphene appear so distinct as to be almost different materials, their Chern index maps are, remarkably, identical. The topological physics of this material is thus strongly robust to lattice relaxations.

Authors with CRIS profile

Simon Theil Naturwissenschaftliche Fakultät Maximilian Fleischmann Lehrstuhl für Theoretische Festkörperphysik Fabian Rost Lehrstuhl für Theoretische Festkörperphysik Florian Wullschläger Interdisziplinäres Zentrum für Molekulare Materialien (ICMM) Bernd Meyer Professur für Computational Chemistry

Additional Organisation(s)

Graduiertenkolleg 2423 Skalenübergreifende Bruchvorgänge: Integration von Mechanik, Materialwissenschaften, Mathematik, Chemie und Physik Computer-Chemie-Centrum (CCC)

Involved external institutions

Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie im Forschungsverbund Berlin e.V. / Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy DE Germany (DE) University of Bristol GB United Kingdom (GB)

How to cite

APA:

Theil, S., Fleischmann, M., Gupta, R., Rost, F., Wullschläger, F., Sharma, S.,... Shallcross, S. (2021). General relation between stacking order and Chern index: A topological map of minimally twisted bilayer graphene. Physical Review B, 104(12). https://doi.org/10.1103/PhysRevB.104.125412

MLA:

Theil, Simon, et al. "General relation between stacking order and Chern index: A topological map of minimally twisted bilayer graphene." Physical Review B 104.12 (2021).

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