English

Equilibrium structure and off-equilibrium kinetics of a magnet with tunable frustration

Statistical Mechanics 2017-11-08 v1

Abstract

We study numerically a two-dimensional random-bond Ising model where frustration can be tuned by varying the fraction aa of antiferromagnetic coupling constants. At low temperatures the model exhibits a phase with ferromagnetic order for sufficiently small values of aa, a<afa<a_f. In an intermediate range af<a<aaa_f<a<a_a the system is paramagnetic, with spin glass order expected right at zero temperature. For even larger values a>aaa>a_a an antiferromagnetic phase exists. After a deep quench from high temperatures, slow evolution is observed for any value of aa. We show that different amounts of frustration, tuned by aa, affect the dynamical properties in a highly non trivial way. In particular, the kinetics is logarithmically slow in phases with ferromagnetic or antiferromagnetic order, whereas evolution is faster, i.e. algebraic, when spin glass order is prevailing. An interpretation is given in terms of the different nature of phase space.

Keywords

Cite

@article{arxiv.1706.03352,
  title  = {Equilibrium structure and off-equilibrium kinetics of a magnet with tunable frustration},
  author = {Federico Corberi and Manoj Kumar and Eugenio Lippiello and Sanjay Puri},
  journal= {arXiv preprint arXiv:1706.03352},
  year   = {2017}
}

Comments

19 pages, 10 figures. To appear on Phys. Rev. E