Hysteretic and intermittent regimes in the subcritical bifurcation of a quasi 1D system of interacting particles - Archive ouverte HAL
Pré-Publication, Document De Travail Année : 2015

Hysteretic and intermittent regimes in the subcritical bifurcation of a quasi 1D system of interacting particles

Christophe Coste
Michel Saint-Jean
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Résumé

In this article, we study the effects of a white gaussian additive thermal noise on a subcritical pitchfork bifurcation. We consider a quasi-1D system of particles that are transversally confined, with short range (non Coulombic) interactions and periodic boundary conditions in the longitudinal direction. In such systems, there is a structural transition from a linear order to a staggered raw, called the zigzag transition. There is a finite range of transverse confinement stiffnesses for which the stable configuration at zero temperature is a localized zigzag pattern surrounded by aligned particles, which evidences the subcriticality of the bifurcation. We show that these configurations remains stable for a wide temperature range. At zero temperature, the transition between a straight line and such localized zigzag patterns is hysteretic. We have studied the influence of the thermal noise on the hysteresis loop. Its description is more difficult than at $T=0$~K since thermally activated jumps between the two configurations always occur and the system can never stay forever in a unique metastable state. Two different regimes have to be considered according to the temperature value with respect to a critical temperature $T_c(\tau_{obs})$ that depends on the observation time $\tau_{obs}$. An hysteresis loop is still observed at low temperature, with a width that decreases as the temperature increases toward $T_c(\tau_{obs})$. In contrast for $T>T_c(\tau_{obs})$ the memory of the initial condition is lost by stochastic jumps between the configurations. The study of the mean residence times in each configurations gives a unique opportunity to precisely determine the barrier height that separates the two configurations, without knowing the complete energy landscape of this many-body system. We also show how to reconstruct the hysteresis loop which would exist at $T=0$~K from high temperature simulations.
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Dates et versions

hal-01216045 , version 1 (16-10-2015)
hal-01216045 , version 2 (29-11-2016)

Identifiants

  • HAL Id : hal-01216045 , version 1

Citer

Tommy Dessup, Christophe Coste, Michel Saint-Jean. Hysteretic and intermittent regimes in the subcritical bifurcation of a quasi 1D system of interacting particles. 2015. ⟨hal-01216045v1⟩
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