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HL: Fachverband Halbleiterphysik
HL 32: Twisted Bilayer Graphene (jointly with DY, MA, HL, DS, O) (joint session TT/HL)
HL 32.5: Vortrag
Dienstag, 17. März 2020, 15:00–15:15, HSZ 201
Quantum diffusion in twisted bilayer graphene — •Guy Trambly de Laissardière1, Omid Faizy Namarvar2,3, Ahmed Missaoui1, Javad Vahedi1,4, Andreas Honecker1, Laurence Magaud2, and Didier Mayou2 — 1Laboratoire de Physique Théorique et Modélisation, CNRS (UMR 8089), Univ. de Cergy-Pontoise, France — 2Institut Néel, CNRS, Univ. Grenoble Alpes, France — 3XLIM, Univ. Limoges, CNRS (UMR 7252), Limoges, France — 4Department of Physics and Earth Sciences, Jacobs University Bremen, Germany
It has been shown theoretically and experimentally that twisted bilayer graphenes (TBG), forming Moiré patterns, confine electrons in a tunable way as a function of the angle of rotation of one layer with respect to the other. Since 2018 the discovery of correlated insulators and superconductivity at so-called "magic angles" has stimulated an avalanche of experimental and theoretical activities. In the framework of the Kubo-Greenwood formula for the conductivity, we present tight-binding calculations of quantum diffusion properties in TBG at various angles including the first magic angle. We analyze in particular the effect of static defects, the effect of an electric bias and electron-electron interactions. One of the main results is the decisive role of inter-band transitions [1] in the conductivity of TBG at the magic angle.
[1] G. Trambly de Laissardière et al., Phys. Rev. B 93, 235135 (2016).