Zobrazeno 1 - 10
of 68
pro vyhledávání: '"Branco, N. S."'
Autor:
Diaz, I J L, Branco, N S
The mean-field and effective-field approximations are applied in the study of magnetic and thermodynamic properties of a spin-$1/2$ Ising system containing three layers, each of which is composed exclusively of one out of two possible types of atoms,
Externí odkaz:
http://arxiv.org/abs/1710.10298
We have studied the presence of plateaus on the low-temperature magnetization of an antiferromagnetic spin-1 chain, as an external uniform magnetic field is varied. A crystal-field interaction is present in the model and the exchange constants follow
Externí odkaz:
http://arxiv.org/abs/1505.04209
In this work we make a numerical study of the dynamic universality class of the Niedermayer algorithm applied to the two-dimensional Potts model with 2, 3, and 4 states. This algorithm updates clusters of spins and has a free parameter, $E_0$, which
Externí odkaz:
http://arxiv.org/abs/1204.4353
Autor:
Diaz, I. J. L., Branco, N. S.
We study the critical behavior of a quenched random-exchange Ising model with competing interactions on a bcc lattice. This model was introduced in the study of the magnetic behavior of Fe_{1-x}Ru_x alloys for ruthenium concentrations x=0%, x=4%, x=6
Externí odkaz:
http://arxiv.org/abs/1202.2104
Autor:
Oliveira, T. P., Branco, N. S.
We employ a mean-field approximation to study the Ising model with aperiodic modulation of its interactions in one spatial direction. Two different values for the exchange constant, $J_A$ and $J_B$, are present, according to the Fibonacci sequence. W
Externí odkaz:
http://arxiv.org/abs/1112.4728
Autor:
Girardi, D., Branco, N. S.
We study the Potts model on a rectangular lattice with aperiodic modulations in its interactions along one direction. Numerical results are obtained using the Wolff algorithm and for many lattice sizes, allowing for a finite-size scaling analyses to
Externí odkaz:
http://arxiv.org/abs/1104.5184
We obtain analitically the $v^2$ dependence of the drag force on a falling sphere close to the drag crisis, as well as the drag coefficient at the drag crisis, with excellent agreement with experiment. We take into account the effects of viscosity in
Externí odkaz:
http://arxiv.org/abs/1009.1536
Autor:
Girardi, D., Branco, N. S.
We calculate the dynamic critical exponent for the Niedermayer algorithm applied to the two-dimensional Ising and XY models, for various values of the free parameter $E_0$. For $E_0=-1$ we regain the Metropolis algorithm and for $E_0=1$ we regain the
Externí odkaz:
http://arxiv.org/abs/1003.3655
Publikováno v:
Solid State Communications, vol. 147, page 494 (2008)
Two one-dimensional spin-1 antiferromagnetic Ising models with a single-ion anisotropy under external magnetic field at low temperatures are exactly investigated by the transfer-matrix technique. The magnetization per spin ($m$) is obtained for the t
Externí odkaz:
http://arxiv.org/abs/0905.0505
Autor:
Paduani, C., Branco, N. S.
The magnetic properties of the $Fe_{1-x}Ru_x$ alloy system for 0 $\leq$ x $\leq$ 0.10 are studied by using a mean-field approximation based on the Bogoliubov inequality. Ferromagnetic Fe-Fe spin correlations and antiferromagnetic Fe-Ru and Ru-Ru exch
Externí odkaz:
http://arxiv.org/abs/0803.3439