title: Topological phase transitions in the golden string-net model.
abstract: We examine the zero-temperature phase diagram of the two-dimensional Levin-Wen string-net model with Fibonacci anyons in the presence of competing interactions. Combining high-order series expansions around three exactly solvable points and exact diagonalizations, we find that the non-Abelian doubled Fibonacci topological phase is separated from two nontopological phases by different second-order quantum critical points, the positions of which are computed accurately. These trivial phases are separated by a first-order transition occurring at a fourth exactly solvable point where the ground-state manifold is infinitely many degenerate. The evaluation of critical exponents suggests unusual universality classes.
authors.affiliation: Lehrstuhl für Theoretische Physik I, Technische Universität Dortmund, Otto-Hahn-Straße 4, 44221 Dortmund, Germany and Laboratoire de Physique Théorique de la Matière Condensée, CNRS UMR 7600, Université Pierre et Marie Curie, 4 Place Jussieu, 75252 Paris Cedex 05, France.
authors.forename: Marc Daniel
authors.initials: MD
authors.lastname: Schulz
authors.affiliation: Lycée Saint-Louis, 44 Boulevard Saint-Michel, 75006 Paris, France.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Dusuel
authors.affiliation: Lehrstuhl für Theoretische Physik I, Technische Universität Dortmund, Otto-Hahn-Straße 4, 44221 Dortmund, Germany.
authors.forename: Kai Phillip
authors.initials: KP
authors.lastname: Schmidt
authors.affiliation: Laboratoire de Physique Théorique de la Matière Condensée, CNRS UMR 7600, Université Pierre et Marie Curie, 4 Place Jussieu, 75252 Paris Cedex 05, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Vidal