We present some numerical results for the Heisenberg spin-glass model with Gaussian interactions, in a three-dimensional cubic lattice. We measure the ac susceptibility as a function of temperature and determine an apparent finite temperature transition which is compatible with the chiral-glass temperature transition for this model. The relaxation time diverges like a power law t,sT−Tcd with Tc...

The spin glass behavior near zero temperature is a complicated matter. To get an easier access to the spin glass order parameter Q(x) and, at the same time, keep track of Qab, its matrix aspect, and hence of the Hessian controlling stability, we investigate an expansion of the free energy functional around its “spherical” approximation. This expansion is obtained by introducing a constraint fie...

We report large-scale simulations of the three-dimensional Edwards–Anderson Ising spin-glass model using the multi-overlap Monte Carlo algorithm. We present our results in the spin-glass phase on free-energy barriers and the non-trivial finite-size scaling behavior of the Parisi order-parameter distribution.  1999 Elsevier Science B.V. All rights reserved. Spin-glass systems [1] are simple mod...

We present results of a Monte Carlo simulation of an Heisenberg Spin Glass model on a hipercubic cell of size 2 in D dimensions. Each spin interacts with D nearest neighbors and the lattice is expected to recover the completely connected (mean field) limit as D → ∞. An analysis of the Binder parameter for D = 8, 9 and 10 shows clear evidence of the presence of a spin glass phase at low temperat...

We report on an extensive study of the influence of spin anisotropy on spin glass aging dynamics. New temperature cycle experiments allow us to compare quantitatively the memory effect in four Heisenberg spin glasses with various degrees of random anisotropy and one Ising spin glass. The sharpness of the memory effect appears to decrease continuously with the spin anisotropy. Besides, the spin ...

Spin glasses are frustrated magnetic systems due to a random distribution of ferroand antiferromagnetic interactions. An experimental three dimensional (3d) spin glass exhibits a second order phase transition to a low temperature spin glass phase regardless of the spin dimensionality. In addition, the low temperature phase of Ising and Heisenberg spin glasses exhibits similar non-equilibrium dy...

A Bethe-Peierls treatment to dilution in short range frustrated magnets and spin liquids is given. The ferromagnetic bonds of a Cayley tree are diluted and a next nearest neighbor antiferromagnetic coupling is added by completing the triangles in a Husimi cactus fashion. A spin glass phase is present at low temperatures and close to the percolation point as soon as frustration is switched on in...