title: Emergent Non-Fermi-Liquid at the Quantum Critical Point of a Topological Phase Transition in Two Dimensions.
abstract: We study the effects of Coulomb interaction between 2D Weyl fermions with anisotropic dispersion which displays relativistic dynamics along one direction and nonrelativistic dynamics along the other. Such a dispersion can be realized in phosphorene under electric field or strain, in TiO_{2}/VO_{2} superlattices, and, more generally, at the quantum critical point between a nodal semimetal and an insulator in systems with a chiral symmetry. Using the one-loop renormalization group approach in combination with the large-N expansion, we find that the system displays interaction-driven non-Fermi liquid behavior in a wide range of intermediate frequencies and marginal Fermi liquid behavior at the smallest frequencies. In the non-Fermi liquid regime, the quasiparticle residue Z at energy E scales as Z∝E^{a} with a>0, and the parameters of the fermionic dispersion acquire anomalous dimensions. In the marginal Fermi-liquid regime, Z∝(|logE|)^{-b} with universal b=3/2.
authors.affiliation: Department of Applied Physics, University of Tokyo, Bunkyo, Tokyo 113-8656, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Isobe
authors.affiliation: RIKEN Center for Emergence Matter Science (CEMS), Wako, Saitama 351-0198, Japan.|Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 151-747, Korea.|Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea.
authors.forename: Bohm-Jung
authors.initials: BJ
authors.lastname: Yang
authors.affiliation: William I. Fine Theoretical Physics Institute and School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA.
authors.forename: Andrey
authors.initials: A
authors.lastname: Chubukov
authors.affiliation: Institutes for Theory of Condensed Matter and for Solid State Physics, Karlsruhe Institute of Technology, D-76131 Karlsruhe, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Schmalian
authors.affiliation: Department of Applied Physics, University of Tokyo, Bunkyo, Tokyo 113-8656, Japan.|RIKEN Center for Emergence Matter Science (CEMS), Wako, Saitama 351-0198, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Nagaosa