title: Chaotic properties of spin lattices near second-order phase transitions.
abstract: We perform a numerical investigation of the Lyapunov spectra of chaotic dynamics in lattices of classical spins in the vicinity of second-order ferromagnetic and antiferromagnetic phase transitions. On the basis of this investigation, we identify a characteristic of the shape of the Lyapunov spectra, the "G-index," which exhibits a sharp peak as a function of temperature at the phase transition, provided the order parameter is capable of sufficiently strong dynamic fluctuations. As part of this work, we also propose a general numerical algorithm for determining the temperature in many-particle systems, where kinetic energy is not defined.
authors.affiliation: Department of Physics, Stockholm University, 106 91 Stockholm, Sweden.
authors.forename: A S
authors.initials: AS
authors.lastname: de Wijn
authors.affiliation: Institute for Theoretical Physics, University of Heidelberg, Philosophenweg 19, 69120 Heidelberg, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Hess
authors.affiliation: Institute for Theoretical Physics, University of Heidelberg, Philosophenweg 19, 69120 Heidelberg, Germany.|Department of Physics, School of Science and Technology, Nazarbayev University 53 Kabanbai Batyr Avenue, Astana 010000, Kazakhstan.|Skolkovo Institute of Science and Technology, 100 Novaya Str., Skolkovo, Moscow Region 143025, Russia.
authors.forename: B V
authors.initials: BV
authors.lastname: Fine