REAL

Diverging dc conductivity due to a flat band in disordered pseudospin-1 Dirac-Weyl fermions

Vigh, Máté and Oroszlány, László and Vajna, Szabolcs and San-Jose, Pablo and Dávid, Gyula and Cserti, József and Dóra, Balázs (2013) Diverging dc conductivity due to a flat band in disordered pseudospin-1 Dirac-Weyl fermions. PHYSICAL REVIEW B CONDENSED MATTER AND MATERIALS PHYSICS (5). pp. 1-5. ISSN 1098-0121

[img]
Preview
Text
Divergin dc conductivity due to a flat band in disordered pseudospin-1 Dirac-Weyl fermions.pdf

Download (235kB) | Preview

Abstract

Several lattices, such as the dice or the Lieb lattice, possess Dirac cones and a flat band crossing the Dirac point, whose effective model is the pseudospin-1 Dirac-Weyl equation. We investigate the fate of the flat band in the presence of disorder by focusing on the density of states (DOS) and dc conductivity. While the central hub-site does not reveal the presence of the flat band, the sublattice resolved DOS on the non-central sites exhibits a narrow peak with height 1/pg with g the dimensionless disorder variance. Although the group velocity is zero on the flat band, the dc conductivity diverges as ln(1/g) with decreasing disorder due to interband transitions around the band touching point between the propagating and the flat band. Generalizations to higher pseudospin are given.

Item Type: Article
Subjects: Q Science / természettudomány > QC Physics / fizika > QC06 Physics of condensed matter / szilárdtestfizika
Depositing User: Mária Kokol
Date Deposited: 27 Mar 2014 10:11
Last Modified: 27 Mar 2014 13:56
URI: http://real.mtak.hu/id/eprint/11175

Actions (login required)

Edit Item Edit Item