Prediction of a Two-Dimensional Organic Topological Insulator

TLDR

Topological insulators are materials with unique quantum transport properties, and while all confirmed examples are inorganic, recent theories suggest that two‑dimensional organic topological insulators could exist in organometallic frameworks, though they have not yet been experimentally realized. The study aims to identify an experimentally synthesized 2D organometallic framework that could serve as an organic topological insulator. The Ni₃C₁₂S₁₂ framework displays nontrivial topological states in both a Dirac band and a flat band, confirming the existence of organic topological insulators.

Abstract

Topological insulators (TI) are a class of materials exhibiting unique quantum transport properties with potential applications in spintronics and quantum computing. To date, all of the experimentally confirmed TIs are inorganic materials. Recent theories predicted the possible existence of organic TIs (OTI) in two-dimensional (2D) organometallic frameworks. However, those theoretically proposed structures do not naturally exist and remain to be made in experiments. Here, we identify a recently experimentally made 2D organometallic framework, consisting of π-conjugated nickel-bis-dithiolene with a chemical formula Ni3C12S12, which exhibits nontrivial topological states in both a Dirac band and a flat band, therefore confirming the existence of OTI.