## Abstract

The authors study diffusion in d=2 percolation clusters at criticality under the influence of an external time-dependent field E(t)=E_{0}sin( omega t). They find that the mean displacement (x(t)) of a random walker is a periodic function with a phase shift phi approximately= pi /3 independent of omega and E_{0}. The amplitude A(E_{0}, omega ) of (x(t)) is linear in E_{0} below a crossover field E*_{0}( omega ). Above E*_{0}( omega ), A(E_{0}, omega ) is strongly non-linear, showing a maximum as a function of E_{0}. They find that both the linear and the non-linear regime can be described by a single scaling function: A(E_{0}, omega ) approximately E_{0} omega ^{-2}d/F(E_{0}/E*_{0}( omega )) where d approximately=2.87 is the diffusion exponent and E*_{0}( omega ) approximately omega ^{beta} with beta approximately=0.3. The linear response regime is reached for E_{0}/ omega ^{beta}<<1.

Original language | English |
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Article number | 012 |

Pages (from-to) | L927-L932 |

Journal | Journal of Physics A: General Physics |

Volume | 19 |

Issue number | 15 |

DOIs | |

State | Published - 1986 |

Externally published | Yes |