Dynamics and hysteresis in square lattice artificial spin ice

Autor: G M Wysin, W A Moura-Melo, L A S Mól, A R Pereira
Jazyk: angličtina
Rok vydání: 2013
Předmět:
Zdroj: New Journal of Physics, Vol 15, Iss 4, p 045029 (2013)
Druh dokumentu: article
ISSN: 1367-2630
DOI: 10.1088/1367-2630/15/4/045029
Popis: Dynamical effects under geometrical frustration are considered in a model for artificial spin ice on a square lattice in two dimensions. Each island of the spin ice has a three-component Heisenberg-like dipole moment subject to shape anisotropies that influence its direction. The model has real dynamics, including rotation of the magnetic degrees of freedom, going beyond the Ising-type models of spin ice. The dynamics is studied using a Langevin equation solved via a second-order Heun algorithm. Thermodynamic properties such as the specific heat are presented for different couplings. A peak in specific heat is related to a type of melting-like phase transition present in the model. Hysteresis in an applied magnetic field is calculated for model parameters where the system is able to reach thermodynamic equilibrium.
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