This article is dedicated to Dieter Vollhardt on the occasion of his 60th birthday.
Anomalous criticality near semimetal-to-superfluid quantum phase transition in a two-dimensional Dirac cone model†
Article first published online: 13 SEP 2011
Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Annalen der Physik
Special Issue: Special Topic Issue “Electronic Correlations in Models and Materials”
Volume 523, Issue 8-9, pages 621–628, August 2011
How to Cite
Obert, B., Takei, S. and Metzner, W. (2011), Anomalous criticality near semimetal-to-superfluid quantum phase transition in a two-dimensional Dirac cone model. Ann. Phys., 523: 621–628. doi: 10.1002/andp.201100039
- Issue published online: 13 SEP 2011
- Article first published online: 13 SEP 2011
- Manuscript Accepted: 15 APR 2011
- Manuscript Received: 15 FEB 2011
- DFG. Grant Number: FOR 723
- Correlated electrons;
- quantum criticality;
- non-Fermi liquid.
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.