Anomalous criticality near semimetal-to-superfluid quantum phase transition in a two-dimensional Dirac cone model

• Published in: Annalen der Physik Vol. 523; no. 8-9; pp. 621 - 628
• Main Authors: Obert, B., Takei, S., Metzner, W.
• Format: Journal Article
• Language: English
• Published: Berlin WILEY-VCH Verlag 01-08-2011; WILEY‐VCH Verlag; Wiley Subscription Services, Inc
• Subjects: Correlated electrons; Critical point; Dispersions; Fluids; Ground state; Helium; Mathematical analysis; non-Fermi liquid; Order parameters; Phase transitions; quantum criticality; Superfluidity; Two dimensional
• ISSN: 0003-3804; 1521-3889
• DOI: 10.1002/andp.201100039

We analyze the scaling behavior at and near a quantum critical point separating a semimetallic from a superfluid phase. To this end we compute the renormalization group flow for a model of attractively interacting electrons with a linear dispersion around a single Dirac point. We study both ground state and finite temperature properties. In two dimensions, the electrons and the order parameter fluctuations exhibit power‐law scaling with anomalous scaling dimensions. The quasi‐particle weight and the Fermi velocity vanish at the quantum critical point. The order parameter correlation length turns out to be infinite everywhere in the semimetallic ground state.
The authors analyze the scaling behavior at and near a quantum critical point separating a semimetallic from a superfluid phase. To this end they compute the renormalization group flow for a model of attractively interacting electrons with a linear dispersion around a single Dirac point. They study both ground state and finite temperature properties.