Chaotic properties of spin lattices near second-order phase transitions

A. S. de Wijn, B. Hess, B. V. Fine
2015 Physical Review E  
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 a part of
more » ... s work, we also propose a general numerical algorithm for determining the temperature in many-particle systems, where kinetic energy is not defined.
doi:10.1103/physreve.92.062929 pmid:26764796 fatcat:yxxoeqce4jb6bi2oajxni3as2i