Two-step photo-induced phase transitions in a two-sublattice model

Y. Otsuka; K. Yonemitsu

doi:doi:10.1051/jp4:2004114152

Issue		J. Phys. IV France Volume 114, April 2004


Page(s)		637 - 639
DOI		https://doi.org/10.1051/jp4:2004114152

J. Phys. IV France 114 (2004) 637
DOI: 10.1051/jp4:2004114152

Two-step photo-induced phase transitions in a two-sublattice model

Y. Otsuka^{1, 1} and K. Yonemitsu^{1, 2, 1}

¹ Department of Theoretical Studies, Institute for Molecular Science, Okazaki 444-8585, Japan
² Graduate University for Advanced Studies, Okazaki 444-8585, Japan

Abstract
As an effective model for the two-step spin transition, we study a two-sublattice spin model that takes into account intra-site antiferromagnetic and inter-site ferromagnetic couplings. Due to the competition between these couplings, the temperature dependence of the high spin fraction shows a two-step transition. We perform Monte Carlo (MC) simulations including a photoexcitation term. The MC dynamics of the high spin fraction shows non-linear characteristics such as step-like changes, threshold-like behavior, and phase separation. Key words. spin-crossover complex, photo-induced phase transition, domain formation.