Ising model

About: Ising model is a research topic. Over the lifetime, 25508 publications have been published within this topic receiving 555000 citations.

Dynamic Monte Carlo Measurement of Critical Exponents.

Abstract: Based on the scaling relation for the dynamics at the early time, a new method is proposed to measure both the static and dynamic critical exponents. The method is applied to the two-dimensional Ising model. The results are in good agreement with the existing results. Since the measurement is carried out in the initial stage of the relaxation process starting from independent initial configurations, our method is efficient.

Ising spinodal decomposition at T=O in one to five dimensions

Abstract: Monte Carlo simulations determine the fraction of not yet flipped spins as a function of time, if the initial spin configuration is random in a nearest-neighbour Ising model. The exponent of Derrida, Bray and Godreche (1994) in one and two dimensions is reconfirmed for much larger systems and generalized to three dimensions. In five and more dimensions, this nearest-neighbour Ising model suggests an asymptotically finite fraction of never flipping spins.

Neutron scattering study of the two-dimensional spin S=1/2 square-lattice Heisenberg antiferromagnet Sr2CuO2Cl2

Abstract: We have carried out a neutron scattering investigation of the static structure factorS(q 2D ) (q 2D is the in-plane wave vector) in the two-dimensional spinS=1/2 square-lattice Heisenberg antiferromagnet Sr2CuO2Cl2. For the spin correlation length ξ we find quantitative agreement with Monte Carlo results over a wide range of temperature. The combined Sr2CuO2Cl2-Monte Carlo data, which cover the length scale from ≈1 to 200 lattice constants, are predicted without adjustable parameteres by renormalized classical theory for the quantum nonlinear sigma model. For the structure factor peakS(0), on the other hand, we findS(0)∼ξ 2 for the reduced temperature range 0.16

A deformed analogue of Onsager’s symmetry in the XXZ open spin chain

Abstract: The XXZ open spin chain with general integrable boundary conditions is shown to possess a q-deformed analogue of the Onsager's algebra as fundamental non-Abelian symmetry which ensures the integrability of the model. This symmetry implies the existence of a finite set of independent mutually commuting nonlocal operators which form an Abelian subalgebra. The transfer matrix and local conserved quantities, for instance the Hamiltonian, are expressed in terms of these nonlocal operators. It follows that Onsager's original approach of the planar Ising model can be extended to the XXZ open spin chain.

Electrostatic analogy for surfactant assemblies

Abstract: We develop a concept of frustrating charges to create a theory of self-assembly. In particular, we note that the constraints of stoichiometry frustrate ordinary phase equilibria and lead to self-assembly of systems such as oil-water-surfactant mixtures. Further we note that at long wavelengths, the constraints of stoichiometry are isomorphic to the constraints of charge neutrality in a specific electrostatic analogy. We expand upon this analogy, first noted by Stillinger, and show that it can be used to derive useful analytical estimates. In addition we use the analogy to create a new model for frustrated systems, and we present Monte Carlo results for this charge frustrated Ising system that exhibits varied behaviors of self-assembly. The Monte Carlo calculations are made possible through the development of an algorithm which permits cluster moves. 9 refs., 5 figs.