Short-time dynamics study of Heisenberg noncollinear magnets

[摘要] A generalized model which describes a family of antiferromagnetic Heisenberg magnets on a three-dimensional stacked triangular lattice is studied. The model contains a constraint parameter which changes the details of the interactions but not the symmetry of the model. We investigate the question of whether a first or second order phase transition occurs in these systems using a short time dynamics method. The effective critical exponents are determined as a function of the constraint parameter. Our results provide strong evidence that the phase transition is first order. In addition, for a particular value of the constraint parameter, the model corresponds to a stacked kagome lattice. In this case, our results also indicate the existence of a finite temperature first order phase transition.

[发布日期] 2007-12-01

[关键词] MONTE-CARLO;BEHAVIOR;MODEL;XY