Titolo:
Linearly driven Random Field Ising Model: hysteresis and avalanches.
(Autori: Giulia Iori, Jordi Ortin e Lluis Carillo)
A system described by a RFIM in absence of thermal fluctuations and
driven by an external field moves from one metastable state to another
through a sequence of collective events, called avalanches. This
avalanche-like motion produces jumps in the magnetization known as
Barkausen noise.
The RFIM have been extensively studied
in the so-called adiabatic approximation: the avalanches are
considered instantaneous on the time-scale of the variation of the
driving field so that the evolution of the system is independent
from the velocity of the applied field.
Motivated by experimental techniques, where the external field
changes at a non-zero rate,
the aim of this work is to study the influence of the driving rate
on the avalanche dynamics of the RFIM. We compute the avalanche
distributions and the area of the hysteresis loop
as a function of the field driving rate and the
level of disorder.