2004/07/31 by Eugenio Lippiello, Federico Corberi, Marco Zannetti · 2 citations
Mathematics · Physics and Astronomy · #Condensed matter physics #Dissipation #Fluctuation-dissipation theorem #Generalization #Ising model #Langevin dynamics #Mathematical analysis #Mathematical physics #Mathematics #Order (exchange) #Physics #Quantum many-body systems #Quantum mechanics #Spectroscopy and Quantum Chemical Studies #Spins #Statistical physics #Theoretical and Computational Physics #cond-mat.stat-mech
paper · pdf · doi:10.1103/physreve.71.036104
published as Phys. Rev. E 71, 036104 (2005) · 12 pages, 5 figures
arxiv created 2005/01/18 · openalex publication_date 2005/03/07 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We derive for Ising spins an off-equilibrium generalization of the fluctuation dissipation theorem, which is formally identical to the one previously obtained for soft spins with Langevin dynamics [L.F. Cugliandolo, J. Kurchan, and G. Parisi, J. Phys. I 4, 1641 (1994)]. The result is quite general and holds both for dynamics with conserved and nonconserved order parameters. On the basis of this fluctuation dissipation relation, we construct an efficient numerical algorithm for the computation of the linear response function without imposing the perturbing field, which is alternative to those of Chatelain [J. Phys. A 36, 10 739 (2003)] and Ricci-Tersenghi [Phys. Rev. E 68, 065104(R) (2003)]. As applications of the new algorithm, we present very accurate data for the linear response function of the Ising chain, with conserved and nonconserved order parameter dynamics, finding that in both cases the structure is the same with a very simple physical interpretation. We also compute the integrated response function of the two-dimensional Ising model, confirming that it obeys scaling chi (t, t(w)) approximately equal to t(-a)(w) f (t/t(w)) , with a =0.26+/-0.01 , as previously found with a different method.