Recent discovery of unconventional superconductivity in twisted bilayer graphene (tBLG) has triggered intensive discussions about the importance of interlayer coupling effects in commensurate tBLG, which was overlooked previously. Much of its macroscale properties, such as conducting electron behavior and light matter interactions in the commensurate tBLG systems remain unknown. Here we present study of the interlayer coupling effects in the twisted 30° bilayer graphene system using surface sensitive low energy electron microscopy (LEEM), Raman scattering and infra-red scattering near-field optical microscopy (IR-sSNOM). Strong crystal structure coupling between two graphene sheets was revealed by a sharp 12-fold symmetrical LEED diffraction pattern. Enhancement of interlayer light scattering was also observed by Raman spectroscopy. Most surprisingly, the plasmonic interaction was observed to be sharply quenched on 30° twisted bilayer graphene in contrast with enhanced plasmonic interaction on non-twisted, bilayer graphene.
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Presenters
Zhongwei Dai
Center for Functional Nanomaterials, Brookhaven National Laboratory
Authors
Zhongwei Dai
Center for Functional Nanomaterials, Brookhaven National Laboratory
Zhaoli Gao
University of Pennsylvania, Department of Physics and Astronomy, University of Pennsylvania
Calley Eads
Center for Functional Nanomaterials, Brookhaven National Laboratory, Univ of Arizona, Brookhaven National Laboratory
Samuel Tenney
Center for Functional Nanomaterials, Brookhaven National Laboratory, Brookhaven National Laboratory
Alan T Johnson
University of Pennsylvania, Department of Physics and Astronomy, University of Pennsylvania, Physics, University of Pennsylvania
Jerzy T. Sadowski
Center for Functional Nanomaterials, Brookhaven National Laboratory, Brookhaven National Laboratory
