Quantum Criticality between Topological and Band Insulators in $3+1$ Dimensions

Quantum Criticality between Topological and Band Insulators in $3 + 1$ Dimensions

Pallab Goswami and Sudip Chakravarty

Phys. Rev. Lett. 107, 196803 – Published 2 November 2011

Abstract

Four-component massive and massless Dirac fermions in the presence of long range Coulomb interaction and chemical potential disorder exhibit striking fermionic quantum criticality. For an odd number of flavors of Dirac fermions, the sign of the Dirac mass distinguishes the topological and the trivial band insulator phases, and the gapless semimetallic phase corresponds to the quantum critical point that separates the two. Up to a critical strength of disorder, the semimetallic phase remains stable, and the universality class of the direct phase transition between two insulating phases is unchanged. Beyond the critical strength of disorder the semimetallic phase undergoes a phase transition into a disorder controlled diffusive metallic phase, and there is no longer a direct phase transition between the two types of insulating phases.

Received 21 April 2011

DOI:https://doi.org/10.1103/PhysRevLett.107.196803

Authors & Affiliations

Pallab Goswami¹ and Sudip Chakravarty²

¹Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA
²Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095-1547, USA