Coupling-reentrant phase transition, complex hysteretic behavior, and efficiency optimization in coupled phase oscillators submitted to colored flashing potentials

S. E. MANGIONI; R. DEZA; H. S. WIO

PHYSICAL REVIEW E - STATISTICAL PHYSICS, PLASMAS, FLUIDS AND RELATED INTERDISCIPLINARY TOPICS

American Physical Society

Año: 2002 vol. 66 p. 511061 - 5110612

1063-651X

A recent mean-field analysis of a model consisting of N nonlinear phase oscillators—under the joint influence of global periodic coupling with strength K0 and of local multiplicative and additive noises—has shown a nonequilibrium phase transition towards a broken-symmetry phase exhibiting noise-induced transport, or ‘‘ratchet’’ behavior. In a previous paper we focused on the relationship between the character of the mean velocity <X>  vs load force F) hysteresis loop, the number of ‘‘homogeneous’’ mean-field solutions, and the shape of the stationary mean-field probability distribution function (PDF). Here we assume that the multiplicative noises of the model are Ornstein-Uhlenbeck with common strength Q and self-correlation time t. By resorting to an effective Markovian approximation, we study the t dependence of the phase boundary, and that of the line signaling the transition from the ‘‘interaction-driven regime’’ to the ‘‘noise-driven regime.’’We also study—for selected representative points of the K0 vs Q phase diagram—the t dependence of the transport properties induced by coupling and colored multiplicative noise ~including the efficiency ´ of the mechanical rectification process! and that of the above-mentioned PDF.N nonlinear phase oscillators—under the joint influence of global periodic coupling with strength K0 and of local multiplicative and additive noises—has shown a nonequilibrium phase transition towards a broken-symmetry phase exhibiting noise-induced transport, or ‘‘ratchet’’ behavior. In a previous paper we focused on the relationship between the character of the mean velocity <X>  vs load force F) hysteresis loop, the number of ‘‘homogeneous’’ mean-field solutions, and the shape of the stationary mean-field probability distribution function (PDF). Here we assume that the multiplicative noises of the model are Ornstein-Uhlenbeck with common strength Q and self-correlation time t. By resorting to an effective Markovian approximation, we study the t dependence of the phase boundary, and that of the line signaling the transition from the ‘‘interaction-driven regime’’ to the ‘‘noise-driven regime.’’We also study—for selected representative points of the K0 vs Q phase diagram—the t dependence of the transport properties induced by coupling and colored multiplicative noise ~including the efficiency ´ of the mechanical rectification process! and that of the above-mentioned PDF.