Edge states in the three-quarter filled system, $\alpha$-(BEDT-TTF)$_2$I$_3$

TL;DR

This paper theoretically investigates edge states in the 2D conductor $$-(BEDT-TTF)$_2$I$_3$, revealing Dirac points and edge states at 3/4 and 1/4 fillings, unlike graphene, with potential for large localization lengths.

Contribution

The study demonstrates the presence of Dirac points and edge states at multiple fillings in $$-(BEDT-TTF)$_2$I$_3$, expanding understanding beyond graphene.

Findings

Dirac points and edge states appear at 3/4 and 1/4 fillings.

Localization length of edge states can become very large.

Edge states are present at fillings other than half filling.

Abstract

We study the edge states in the two-dimensional conductor $\alpha$-(BEDT-TTF)$_2$I$_3$ theoretically. We show that the Dirac points and the edge states appear at the 3/4 and 1/4 filling as well as the half filling, due to four sites in the unit cell. This situation is in contract with the graphene, where the Dirac points and the edge states appear only at the half filling case. It is shown that the localization length of the edge states can become very large.