Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Journal of Physics A Mathematical and General

Nonequilibrium spin models with Ising universal behaviour

Mário J. de Oliveira, José F. F. Mendes, M. Santos

Published May 21, 1993• 133 citations
Publisher

Abstract

The properties of a family of nonequilibrium spin models with up-down symmetry on a square lattice are determined by a mean-field pair approximation and by Monte Carlo simulation. The phase diagram in the parameter space displays a critical line that terminates at a first-order critical point. It is found that the critical exponents are the same as those of the equilibrium Ising model.

DOI
10.1088/0305-4470/26/10/006

Related papers

Phase Diagram and Critical Exponents of the ±J Ising Model in Finite Dimensions by Monte Carlo Renormalization Group

Yukiyasu Ozeki, Hidetoshi Nishimori

We have performed large-scale numerical simulations for the ± J Ising model on the simple cubic and the square lattices with asymmetric weight of ferromagnetic and antiferromagnetic bonds. The Monte Carlo renormalization group method is used to estimate T c , γ/ν, β/ν and ν at various points along the phase boundary between ferromagnetic and paramagnetic phases including the tricritical point. The obtained values of T c and the resulting phase diagrams of the simple cubic and the square lattices are much more accurate than those estimated so far. In the simple cubic lattice, we find evidence for the possibility that universality of the ferromagnetic critical exponents holds along the critical line except at the tricritical point, while weak universality holds even at the tricritical point. Weak universality seems to hold also in the square lattice.

Journal of the Physical Society of Japan•Apr 1, 1987•85 citations

Critical Properties of a Spin-3/2 Ising Model on a Square Lattice

Norihiro Tsushima, Yasushi Honda, Tsuyoshi Horiguchi

We investigate a spin-3/2 Ising model on a square lattice by using Monte Carlo (MC) simulations and a density matrix renormalization group (DMRG) method. We obtain phase diagrams of the ground state. We carried out the MC simulations in order to calculate the critical temperature and the critical exponent η. We estimate the critical exponents ν, α and γ by using a finite size scaling analysis. We also calculate the critical temperature, the central charge c and the critical exponent ν by using the DMRG method. From the results obtained by the MC simulations and by the DMRG method, we discuss a universality class of the system. It is found that the values of critical exponents are determined by means of the degeneracy of the ground state. This result suggests that the universality does not hold for the spin-3/2 Ising model. Furthermore we find a possibility of a breakdown of the hyperscaling law. We also confirm that the ferrimagnetic phase exists in a parameter region where the ground state has a fourfold degeneracy, and that a transition between the ferrimagnetic phase and the ferromagnetic phase exists in addition to that between the ferromagnetic phase and the paramagnetic phase.

Journal of the Physical Society of Japan•Oct 15, 1997•26 citations

Non-Equilibrium Critical Dynamics of the Kinetic Baxter Model

Hiroshi Takano

The non-equilibrium critical dynamics of the Baxter model is studied through Monte Carlo simulations. The single-spin-flip stochastic dynamics is introduced on the basis of the formulation of the model as an Ising-type model on the square lattice with next-nearest-neighbor and four-spin interactions. At several points on the critical line, the dynamic critical exponent z and the critical exponent \bar λ c , which characterizes the non-equilibrium critical relaxation, are estimated for the two order parameters of the model, the magnetization and the polarization. For both order parameters, the estimated \bar λ c varies systematically along the critical line. On the other hand, the estimated z is almost constant. This suggests that while the exponent z is universal, the exponent \bar λ c is not.

Journal of the Physical Society of Japan•Mar 15, 1996•2 citations

Non-equilibrium phase transitions in one-dimensional kinetic Ising models

Nóra Menyhárd, Géza Ódor

A family of nonequilibrium kinetic Ising models, introduced earlier, evolving under the competing effect of spin flips at zero temperature and nearest-neighbour random spin exchanges, is further investigated. By increasing the range of spin exchanges and/or their strength the nature of the phase transition 'Ising-to-active' becomes of (dynamic) mean-field type and a first-order tricritical point is located at the Glauber ( delta =0) limit. Corrections to the mean-field theory are evaluated up to sixth order in a cluster approximation and found to give good results concerning the phase boundary and the critical exponent beta of the order parameter which is obtained as beta approximately=1.0.

arXiv:cond-mat/9504061•Journal of Physics A Mathematical and General•Aug 21, 1995•50 citations

Monte Carlo studies of critical phenomena in mixed spin-3/2 and spin-5/2 Ising model on square lattice

N. De La Espriella, J. Madera Yancez, M. S. Páez Mesa

"We used a Monte Carlo simulation to analize the magnetic behavior of Ising model of mixed spins S A i = ß3=2 ; ß1=2 and æ B j = ß 5 = 2 ; ß 3 = 2 ; ß 1 = 2 , on a square lattice. Were studied the possible critical phenomena that may emerge in the region around the multiphase point (D= j J 1 j = ° 3 ;J 2 = j J 1 j = 1) and the dependence of the phase diagrams with the intensities of the anisotropy field of single ion (D= j J 1 j ) and the ferromagnetic coupling of exchange spin S A i (J 2 = j J 1 j). The system displays first order phase transitions in a certain range of the parameters of the Hamiltonian, which depend on D= j J 1 j and j J 2 = j J 1 j . In the plane (D= j J 1 j ;k B T= j J 1 j), the de- crease of j D= j J 1 jj , implies that the critical temperature, T c , increases and the first order transition temperature, T t , decreases. In the plane (J2 = j J 1 j ;k B T= j J 1 j ), T c increases with the increasing of J 2 = j J 1 j , while that T t decreases."

Revista Mexicana de Física•Jan 1, 2014•7 citations

The square-lattice Ising model with first and second neighbour interactions

J. Oitmaa

The critical behaviour of the square-lattice Ising model, with nearest and next-nearest neighbour interactions of either sign, has been investigated by means of high-temperature series. lhe location of the critical lines in the coupling constant plane has been accurately determined. Along the critical line which corresponds to transitions to the layered or superantiferromagnetic state a breakdown of universality is observed and explicit numerical estimates obtained for the exponent of the ordering susceptibility.

Journal of Physics A Mathematical and General•May 1, 1981•109 citations
The properties of a family of nonequilibrium spin models with up-down symmetry on a square lattice are determined by a mean-field pair approximation and by Monte Carlo simulation. The phase diagram in the parameter space displays a critical line that terminates at a first-order critical point. It is found that the critical exponents are the same as those of the equilibrium Ising model.
We have performed large-scale numerical simulations for the ± J Ising model on the simple cubic and the square lattices with asymmetric weight of ferromagnetic and antiferromagnetic bonds. The Monte Carlo renormalization group method is used to estimate T c , γ/ν, β/ν and ν at various points along the phase boundary between ferromagnetic and paramagnetic phases including the tricritical point. The obtained values of T c and the resulting phase diagrams of the simple cubic and the square lattices are much more accurate than those estimated so far. In the simple cubic lattice, we find evidence for the possibility that universality of the ferromagnetic critical exponents holds along the critical line except at the tricritical point, while weak universality holds even at the tricritical point. Weak universality seems to hold also in the square lattice.
We investigate a spin-3/2 Ising model on a square lattice by using Monte Carlo (MC) simulations and a density matrix renormalization group (DMRG) method. We obtain phase diagrams of the ground state. We carried out the MC simulations in order to calculate the critical temperature and the critical exponent η. We estimate the critical exponents ν, α and γ by using a finite size scaling analysis. We also calculate the critical temperature, the central charge c and the critical exponent ν by using the DMRG method. From the results obtained by the MC simulations and by the DMRG method, we discuss a universality class of the system. It is found that the values of critical exponents are determined by means of the degeneracy of the ground state. This result suggests that the universality does not hold for the spin-3/2 Ising model. Furthermore we find a possibility of a breakdown of the hyperscaling law. We also confirm that the ferrimagnetic phase exists in a parameter region where the ground state has a fourfold degeneracy, and that a transition between the ferrimagnetic phase and the ferromagnetic phase exists in addition to that between the ferromagnetic phase and the paramagnetic phase.
The non-equilibrium critical dynamics of the Baxter model is studied through Monte Carlo simulations. The single-spin-flip stochastic dynamics is introduced on the basis of the formulation of the model as an Ising-type model on the square lattice with next-nearest-neighbor and four-spin interactions. At several points on the critical line, the dynamic critical exponent z and the critical exponent \bar λ c , which characterizes the non-equilibrium critical relaxation, are estimated for the two order parameters of the model, the magnetization and the polarization. For both order parameters, the estimated \bar λ c varies systematically along the critical line. On the other hand, the estimated z is almost constant. This suggests that while the exponent z is universal, the exponent \bar λ c is not.
A family of nonequilibrium kinetic Ising models, introduced earlier, evolving under the competing effect of spin flips at zero temperature and nearest-neighbour random spin exchanges, is further investigated. By increasing the range of spin exchanges and/or their strength the nature of the phase transition 'Ising-to-active' becomes of (dynamic) mean-field type and a first-order tricritical point is located at the Glauber ( delta =0) limit. Corrections to the mean-field theory are evaluated up to sixth order in a cluster approximation and found to give good results concerning the phase boundary and the critical exponent beta of the order parameter which is obtained as beta approximately=1.0.
"We used a Monte Carlo simulation to analize the magnetic behavior of Ising model of mixed spins S A i = ß3=2 ; ß1=2 and æ B j = ß 5 = 2 ; ß 3 = 2 ; ß 1 = 2 , on a square lattice. Were studied the possible critical phenomena that may emerge in the region around the multiphase point (D= j J 1 j = ° 3 ;J 2 = j J 1 j = 1) and the dependence of the phase diagrams with the intensities of the anisotropy field of single ion (D= j J 1 j ) and the ferromagnetic coupling of exchange spin S A i (J 2 = j J 1 j). The system displays first order phase transitions in a certain range of the parameters of the Hamiltonian, which depend on D= j J 1 j and j J 2 = j J 1 j . In the plane (D= j J 1 j ;k B T= j J 1 j), the de- crease of j D= j J 1 jj , implies that the critical temperature, T c , increases and the first order transition temperature, T t , decreases. In the plane (J2 = j J 1 j ;k B T= j J 1 j ), T c increases with the increasing of J 2 = j J 1 j , while that T t decreases."
The critical behaviour of the square-lattice Ising model, with nearest and next-nearest neighbour interactions of either sign, has been investigated by means of high-temperature series. lhe location of the critical lines in the coupling constant plane has been accurately determined. Along the critical line which corresponds to transitions to the layered or superantiferromagnetic state a breakdown of universality is observed and explicit numerical estimates obtained for the exponent of the ordering susceptibility.