TWISTED BI LAYER GRAPHENE A NEW CONCEPT OF CRYSTALS, MOIRÉ AND QUASI CRYSTALS || By Prof S. Tanaka (Kyushu University)

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    Supported by JICA  the JICA Research Project of “The Establishment of Nanocharacterization Platform for Research on Functional Materials and Devices”

Joint Research Seminar/Lecture by Prof Satoru Tanaka (Kyushu University)

Recently, a new concept of crystals has emerged in bi layer graphene system. By relative rotation of bi layer graphene in plane it induces a moirépotential or quasi crystal symmetry. The former forms twisted bilayergraphene ( which especially indicates unique electronic structures at low rotation angles Superconductivity was reported at 1.05 degree which is called “a magic angle”. Dramatic Fermi velocity renormalization is also expected by theory. The latter is a quasi crystal which appears at 30 degree rotated TBG 12 fold rotational symmetry was experimentally confirmed in electronicstructures.

TBG has normally been fabricated by tape exfoliation and transferring processes. However, these processes have potential difficulties in obtaining large areas, precise control of the rotation angle, and contaminant free interlayer structures. A large area sample is especially essential to evaluate electronic structure by macro probe characterizations such as angle resolved photoemission spectroscopy ( Thus, we aimed at solving these problems by direct transfer of newly developed CVD grown graphene
on SiC in vacuum In this seminar. I discuss the details of our approach to achieving TBGs and unique electronic structures evaluated by ARPES

Prof Satoru Tanaka is a professor at Kyushu University, Japan in the Department of Applied Quantum Physics and Nuclear Engineering for the last 15 years Previously, he served five years as a lecturer and associate professor at Hokkaido University, Japan in the Research Institute for Electronic Science He has completed his Bachelor of Science in Materials Science from Waseda University, Japan and his PhD in Materials Science and Engineering from North Carolina State University, United States of America He is
also affiliated to several academic societies such as Japan Physical Society, Japanese Society of Applied Physics and The Japan Society of Vacuum and Surface Science