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arXiv · cond-mat/0607069

Influence of the driving mechanism on the response of systems with athermal dynamics: the example of the random-field Ising model

Abstract

We investigate the influence of the driving mechanism on the hysteretic response of systems with athermal dynamics. In the framework of local-mean field theory at finite temperature (but neglecting thermallly activated processes), we compare the rate-independent hysteresis loops obtained in the random field Ising model (RFIM) when controlling either the external magnetic field $H$ or the extensive magnetization $M$. Two distinct behaviors are observed, depending on disorder strength. At large disorder, the $H$-driven and $M$-driven protocols yield identical hysteresis loops in the thermodynamic limit. At low disorder, when the $H$-driven magnetization curve is discontinuous (due to the presence of a macroscopic avalanche), the $M$-driven loop is re-entrant while the induced field exhibits strong intermittent fluctuations and is only weakly self-averaging. The relevance of these results to the experimental observations in ferromagnetic materials, shape memory alloys, and other disordered systems is discussed.

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BibTeXRIS

Xavier Illa, Martin-Luc Rosinberg, Eduard Vives. 2006-07-04. Influence of the driving mechanism on the response of systems with athermal dynamics: the example of the random-field Ising model. https://doi.org/10.1103/physrevb.74.224403

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