title: Quantum and classical glass transitions in LiHoxY1-xF4.
abstract: When performed in the proper low-field, low-frequency limits, measurements of the dynamics and the nonlinear susceptibility in the model Ising magnet in a transverse field LiHo(x)Y(1-x)F(4) prove the existence of a spin-glass transition for x=0.167 and 0.198. The classical behavior tracks for the two concentrations, but the behavior in the quantum regime at large transverse fields differs because of the competing effects of quantum entanglement and random fields.
authors.affiliation: The James Franck Institute and Department of Physics, The University of Chicago, Chicago, IL 60637, USA.
authors.forename: C
authors.initials: C
authors.lastname: Ancona-Torres
authors.forename: D M
authors.initials: DM
authors.lastname: Silevitch
authors.forename: G
authors.initials: G
authors.lastname: Aeppli
authors.forename: T F
authors.initials: TF
authors.lastname: Rosenbaum