Avalanches in mean-field models and the Barkhausen noise in spin-glasses

, and

Published 21 September 2010 Europhysics Letters Association
, , Citation P. Le Doussal et al 2010 EPL 91 57004 DOI 10.1209/0295-5075/91/57004

0295-5075/91/5/57004

Abstract

We obtain a general formula for the distribution of sizes of "static avalanches", or shocks, in generic mean-field glasses with replica-symmetry-breaking (RSB) saddle points. For the Sherrington-Kirkpatrick (SK) spin-glass it yields the density ρ(ΔM) of the sizes of magnetization jumps ΔM along the equilibrium magnetization curve at zero temperature. Continuous RSB allows for a power-law behavior ρ(ΔM)∼1/(ΔM)τ with exponent τ=1 for SK, related to the criticality (marginal stability) of the spin-glass phase. All scales of the ultrametric phase space are implicated in jump events. Similar results are obtained for the sizes S of static jumps of pinned elastic systems, or of shocks in Burgers turbulence in large dimension. In all cases with a 1-step solution, ρ(S)∼SeAS2. A simple interpretation relating droplets to shocks, and a scaling theory for the equilibrium analog of Barkhausen noise in finite-dimensional spin-glasses are discussed.

Export citation and abstract BibTeX RIS

10.1209/0295-5075/91/57004