forgot password?
register here
Research articles
  search articles
  reviews guidelines
  articles index
My Pages
my alerts
  my messages
  my reviews
  my favorites
Members: 2659
Articles: 1'969'991
Articles rated: 2572

08 July 2020
  » arxiv » cond-mat/0510731

  Article overview

Spin, bond and global fluctuation-dissipation relations in the non-equilibrium spherical ferromagnet
A. Annibale ; P. Sollich ;
Date 27 Oct 2005
AbstractWe study the out-of-equilibrium dynamics of the spherical ferromagnet after a quench to its critical temperature. We calculate correlation and response functions for spin observables which probe lengthscales much larger than the lattice spacing but smaller than the system size, and find that the asymptotic fluctuation-dissipation ratio (FDR) X^inf is the same as for local observables. This is consistent with our earlier results for the Ising model in dimension d=1 and d=2. We also check that bond observables, both local and long-range, give the same asymptotic FDR. In the second part of the paper the analysis is extended to global observables, which probe correlations among all N spins. Here non-Gaussian fluctuations arising from the spherical constraint need to be accounted for, and we develop a systematic expansion in 1/sqrt{N} to do this. Applying this to the global bond observable, i.e. the energy, we find that non-Gaussian corrections change its FDR to a nontrivial value which we calculate exactly for all dimensions d>2. Finally, we consider quenches from magnetized initial states. Here even the FDR for the global spin observable, i.e. the magnetization, is nontrivial. It differs from the one for unmagnetized states even in d>4, signalling the appearance of a distinct dynamical universality class of magnetized critical coarsening. For lower d the FDR is irrational even to first order in 4-d and d-2, the latter in contrast to recent results for the n-vector model.
Source arXiv, cond-mat/0510731
Services Forum | Review | PDF | Favorites   
Visitor rating: did you like this article? no 1   2   3   4   5   yes

No review found.
 Did you like this article?

This article or document is ...
of broad interest:
Global appreciation:

  Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.

browser CCBot/2.0 (
» my Online CV
» Free

News, job offers and information for researchers and scientists:
home  |  contact  |  terms of use  |  sitemap
Copyright © 2005-2020 - Scimetrica