The coexistence of Dirac cones and Fermi arcs in a graphene/WTe2 heterostructure

Abstract

We report on the electronic properties of a van der Waals heterostructure formed by graphene and a type-II Weyl semimetal (T_d-WTe₂), hosting features of both Dirac and Weyl semimetals. By combining angle-resolved photoemission spectroscopy (ARPES), scanning tunnelling microscopy and spectroscopy (STM/STS), and density functional theory (DFT) calculations, we directly visualise how the interlayer interaction modifies the electronic structures of both materials in the heterostructure. Furthermore, STM reveals that the local twist angle between the graphene and the Weyl semimetal affects the appearance of moiré patterns in the heterostructure, which in turn suggests a twist-angle-dependent modulation of the interlayer interaction. Finally, we also show XPS 4d lines splitting for Te related to the local environment of tellurium atoms. Our findings highlight the importance of controlling twist angles and interlayer interactions for electronics and twistronics applications based on novel quantum materials.