Quasiperiodic modulation of electronic states at edges of tellurium nanoribbons on graphene/6H-SiC(0001)

Trigonal tellurium with helical structure exhibits intriguing properties due to its inherent chirality, which has attracted considerable research interest recently. Using cryogenic scanning tunneling microscopy/spectroscopy and density functional theory calculations, we investigated quasiperiodic defects at particular edges of Te nanoribbons grown on graphene/SiC(0001) substrate. The detailed topography of edge defects reveals the chirality of Te nanoribbon, and the defects induce a quasiperiodic modulation of the electronic states along the edge. The average period of the edge defects varies with the twist angle between Te nanoribbon and substrate, implying the electronic modulation can be tuned by the interfacial interaction. Based on the morphology analyses and modeled calculations, we further propose the growth mechanism of the Te nanoribbons.