Tight-Binding Model and Electronic Property of Dirac Nodal Line in Single-Component Molecular Conductor [Pt(dmdt)$_{2}$]

TL;DR

This paper develops a three-orbital tight-binding model for the Dirac nodal line in [Pt(dmdt)$_{2}$], revealing edge states, topological features, and magnetic properties consistent with experiments, and predicts its topological semimetal nature.

Contribution

It introduces a novel tight-binding model based on Wannier fitting for [Pt(dmdt)$_{2}$], elucidating its topological and magnetic properties with first-principles validation.

Findings

Logarithmic peaks in local density of states near Fermi energy.

Edge states appear between Dirac nodal lines.

[Pt(dmdt)$_{2}$] is a topological nodal line semimetal with spin-orbit coupling.

Abstract

Motivated by the recent discovery of Dirac nodal line in the single-component molecular conductor [Pt(dmdt)$_{2}$], we propose a three-orbital tight-binding model based on the Wannier fitting of the first-principles calculation, and address the problems of edge states, topological properties and magnetic susceptibility. We find that logarithmic peaks of the local density of states emerge near the Fermi energy, owing to pseudo-one-dimensional edge states that appear between the Dirac nodal lines. Magnetic susceptibility calculated in our model can explain the experimental result at a high temperature. In the presence of a realistic spin-orbit coupling, we show that [Pt(dmdt)$_{2}$] is a topological nodal line semimetal with isolated electron and hole pockets.