Flat AgTe Honeycomb Monolayer with Topologically Nontrivial States

Abstract

The intriguing properties, especially Dirac physics in graphene, have inspired the pursuit of two-dimensional materials in honeycomb structure. Here we achieved a monolayer transition metal monochalcogenide AgTe on Ag(111) by tellurization of the substrate. High-resolution scanning tunneling microscopy, combined with low-energy electron diffraction, angle-resolved photoemission spectroscopy, and density functional theory calculations, demonstrates the planar honeycomb structure of AgTe. The first principle calculations further reveal that, protected by the in-plane mirror reflection symmetry, two Dirac node-line Fermions exist in the electronic structures of free-standing AgTe when spin-orbit coupling (SOC) is ignored. While in fact the SOC leads to the gap opening, and resulting in the emergence of the topologically nontrivial quantum spin Hall edge state. Importantly, our experiments evidence the chemical stability of the monolayer AgTe in ambient conditions. It is possible to study AgTe by more ex-situ measurements and even to apply it in novel electronic devices.

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• In-situ exfoliation method of large-area 2D materials
• Optically-Controlled Orbitronics on a Triangular Lattice
• Density-independent plasmons for terahertz-stable topological metamaterials
• Formation of a Te-Ag Honeycomb Alloy: A New Type of Two-Dimensional Material
• A new alloy for Al-chalcogen system: AlSe surface alloy on Al (111)
• Honeycomb lattice in metal-rich chalcogenide Fe2Te
• Epitaxial fabrication of AgTe monolayer on Ag(111) and the sequential growth of Te film