25 citations · 100 across the 14 of their papers we have counts for
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Spin- ferromagnetic Heisenberg model with an easy-plane crystal field on the cubic lattice: A bosonic approach
D. C. Carvalho, A. S. T. Pires, L. A. S. Mól
We examine the phase diagram of the spin- ferromagnetic Heisenberg model with an easy-plane crystal field on the cubic lattice, in which is the ferromagnetic…
Phase transitions in the two-dimensional Anisotropic Biquadratic Heisenberg Model
Antônio R. Moura, Antônio S. T. Pires, Afrânio R. Pereira
In this paper we study the influence of the single-ion anisotropy in the two-dimensional biquadratic Heisenberg model (ABHM) on the square lattice at zero and finite low temperatur…
Nonlinear sigma model of a spin ladder containing a static single hole
A. R. Pereira, E. Ercolessi, A. S. T. Pires
In this letter we extend the nonlinear sigma model describing pure spin ladders with an arbitrary number of legs to the case of ladders containing a single static hole. A simple im…
Comment on ``Magnon wave forms in the presence of a soliton in two--dimensional antiferromagnets with a staggered field''
Denis D. Sheka
Very recently Fonseca and Pires [Phys. Rev. B 73, 012403(2006)] have studied the soliton--magnon scattering for the isotropic antiferromagnet and calculated ``exact'' phase shifts,…
Spin Dynamics in the Two-Dimensional Spin 1/2 Heisenberg Antiferromagnet
A. F. Albuquerque, A. S. T. Pires, M. E. Gouvea
We present low-temperature dynamic properties of the quantum two-dimensional antiferromagnetic Heisenberg model with spin S=1/2. The calculation of the dynamic correlation function…
Vortices in the presence of a nonmagnetic atom impurity in 2D XY ferromagnets
L. A. S. Mól, A. R. Pereira, A. S. T. Pires
Using a model of nonmagnetic impurity potential, we have examined the behavior of planar vortex solutions in the classical two-dimensional XY ferromagnets in the presence of a spin…