ChemInform Abstract: Relaxation and Critical Dynamics in Spin Glasses

Deepak Kumar

Vladimir V. Prudnikov, G. B. Teǐtel'Baum

L. Lundgren, Per Nordblad, Peter Svedlindh

The relaxation behavior of spin glasses has been analyzed in the framework of the critical fractal-cluster model. It is found that the relaxation rate of the magnetization can be expressed as $\frac{\ensuremath{\partial}m}{\ensuremath{\partial}\mathrm{ln}t}\ensuremath{\propto}{t}^{\ensuremath{-}\frac{\ensuremath{\beta}}{z\ensuremath{\nu}}}\mathrm{exp}[\ensuremath{-}{(\frac{t}{{\ensuremath{\tau}}_{\ensuremath{\xi}}})}^{\frac{\ensuremath{\beta}\ensuremath{\delta}}{z\ensuremath{\nu}}}]$, where $\ensuremath{\beta}$, $\ensuremath{\delta}$, $z$, $\ensuremath{\nu}$ are standard static and dynamic critical exponents and ${\ensuremath{\tau}}_{\ensuremath{\xi}}$ is the relaxation time of a characteristic cluster which diverges at the spin-glass freezing temperature ${T}_{g}$. The expression is valid through ${T}_{g}$ and is found to describe excellently the fundamental features of the relaxation in real spin glasses.

I. Riess, Moshe Fibich, A. Ron

David Carpentier, E. Orignac, Guillame Paulin +1 more

Serge Galam, A. Mauger

Postulating homogeneity for the relaxation function, we show that the standard dynamic scaling hypothesis is recovered and that effective relaxation times must decreme upon increasing Kadanoff's blocks sizes. In the case of spin glasses our results are naturally obtained within a diffusion process in the phase space among eigenstates available to the spin system. The model suggests that the critical slowing-down in spin glasses does not result from hierarchically constrained dynamics.