Bulk Dirac points in distorted spinels

Phys Rev Lett. 2014 Jan 24;112(3):036403. doi: 10.1103/PhysRevLett.112.036403. Epub 2014 Jan 22.

Abstract

We report on a Dirac-like Fermi surface in three-dimensional bulk materials in a distorted spinel structure on the basis of density functional theory as well as tight-binding theory. The four examples we provide in this Letter are BiZnSiO4, BiCaSiO4, BiAlInO4, and BiMgSiO4. A necessary characteristic of these structures is that they contain a Bi lattice which forms a hierarchy of chainlike substructures, with consequences for both fundamental understanding and materials design.