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DY: Fachverband Dynamik und Statistische Physik
DY 40: Posters II
DY 40.40: Poster
Thursday, March 17, 2011, 17:00–19:00, P3
Quantum Criticality in the 3d Gross-Neveu Model from the Functional Renormalization Group — Jens Braun, Holger Gies, and •Daniel David Scherer — Theoretisch-Physikalisches Institut, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, D-07743 Jena, Germany
Using the functional renormalization group, we study the fixed-point structure of the three dimensional Gross-Neveu model describing planar Dirac fermions interacting in a scalar-scalar channel. We employ both a purely fermionic as well as a partially bosonized language. We find non-Gaußian fixed points responsible for gap generation by a second order quantum phase transition in both formulations, the universal critical exponents of which we determine quantitatively as a function of flavor number Nf. We also make contact to the large-Nf expansion. In this limit, the fixed-point action as well as all universal critical exponents can be computed analytically.