Anomalous electron-phonon coupling in magic-angle twisted bilayer graphene.

ORAL

Abstract

We investigate the electron-phonon coupling properties of magic-angle twisted bilayer graphene (MATBG) using gate-dependent Raman spectroscopy. We use illumination from the bellow and ion-gate to dope MATBG highly. Thus, we monitor the electron-phonon coupling through the C-C stretching mode (G band) linewidth as a function of gate voltage. We then compare the MATBG results with large-angle twisted bilayer graphene and Bernal bilayer. We support our results with an atomistic model that reveals a unique MATBG electron-phonon coupling signature influenced by its singular electronic and solitonic structures. Our results point to a relationship between electron-phonon

coupling and the strongly correlated phenomena in MATBG.

*The authors thank Prof Leaonardo C. Campos for helpful discussions. This workwas supported by CNPq (302775/2018-8), CAPES (RELAII and 88881.198744/2018-01)and FAPEMIG, Brazil. A.C.G. acknowledges partial support from DoE Award No.DE-SC0008807. V-H.N. and J.-C.C. acknowledge financial support from the FédérationWallonie-Bruxelles through the ARC on 3D nano-architecturing of 2D crystals (16/21-077), from the European Unions Horizon 2020 Research Project and Innovation Pro-gram Graphene Flagship Core3 (881603), from the Flag-Era JTC project \TATTOOS"(R.8010.19), and from the Belgium FNRS through the research project (T.0051.18). V.M.,M.L acknowledge support from NY State Empire State Developments Division of Science,Technology and Innovation (NYSTAR). Computational resources have been provided bythe CISM supercomputing facilities of UCLouvain and the CECI consortium funde

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Presenters

  • Andreij Gadelha

    • University of Colorado, Boulder

Authors

  • Andreij Gadelha

    • University of Colorado, Boulder