Particle transport and finite-size effects in Lorentz channels with finite horizons


Date

2025-02

Publication Type

Journal Article

ETH Bibliography

yes

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Abstract

Particle transport is investigated in a finite-size realization of the classical Lorentz gas model. We consider point particles moving at constant speed in a 2D rectangular strip of finite length, filled with circular scatterers sitting at the vertices of a triangular lattice. Particles are injected at the left boundary with a prescribed rate, undergo specular reflections when colliding with the scatterers and the horizontal boundaries of the channel, and are finally absorbed at the left or the right boundary. Thanks to the equivalence with give Correlated Random Walks, in the finite horizon case, we show that the inverse probability that a particle exits through the right boundary depends linearly on the number of cells in the channel. A non-monotonic behavior of such probability as a function of the density of scatterers is also discussed and traced back analytically to the geometric features of a single trap. This way, we do not refer to asymptotic quantities and we accurately quantify the finite size effects. Our deterministic model provides a microscopic support for a variety of phenomenological laws, e.g. the Darcy’s law for porous media and the Ohm’s law in electronic transport.

Publication status

published

Editor

Book title

Volume

472

Pages / Article No.

134512

Publisher

Elsevier

Event

Edition / version

Methods

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Subject

Lorentz channel; Finite size effects; Correlated random walk; Passage time; Statistical mechanics

Organisational unit

03986 - Gambardella, Pietro / Gambardella, Pietro check_circle

Notes

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