title: Fidelity approach to the disordered quantum XY model.
abstract: We study the random XY spin chain in a transverse field by analyzing the susceptibility of the ground state fidelity, numerically evaluated through a standard mapping of the model onto quasifree fermions. It is found that the fidelity susceptibility and its scaling properties provide useful information about the phase diagram. In particular it is possible to determine the Ising critical line and the Griffiths phase regions, in agreement with previous analytical and numerical results.
authors.affiliation: Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089, USA. garneron@usc.edu
authors.forename: Silvano
authors.initials: S
authors.lastname: Garnerone
authors.forename: N Tobias
authors.initials: NT
authors.lastname: Jacobson
authors.forename: Stephan
authors.initials: S
authors.lastname: Haas
authors.forename: Paolo
authors.initials: P
authors.lastname: Zanardi