Electronic structure of 3°-twisted bilayer graphene on 4H-SiC(0001)

The electronic structure of 3 degrees-twisted bilayer graphene (TBG) is studied by angle-resolved photoelectron spectroscopy (ARPES). Sub-mm-sized TBG prepared by direct bonding in a high vacuum enabled us to use conventional ARPES band mapping with synchrotron light. The results indicate that strong interlayer coupling makes a moire potential for the Dirac electrons and significantly modifies the graphene bands around the (K) over bar points such as the band splitting and electron velocity reduction. The observed electronic structure is consistently reproduced by tight-binding calculations combined with a band unfolding method.

Automated summary

The electronic structure of 3 degrees-twisted bilayer graphene was studied using ARPES, showing that strong interlayer coupling significantly modifies the Dirac electrons' properties. The observed electronic structure was consistently reproduced by tight-binding calculations and band unfolding method.