Force-velocity relation and density profiles for biased diffusion in an adsorbed monolayer

O. Benichou 1, 2, A. M. Cazabat 3, J. De Coninck, M. Moreau 2, G. Oshanin 2

Physical Review B 63 (2001) 235413

In this paper, which completes our earlier short publication [Phys. Rev. Lett. 84, 511 (2000)], we study dynamics of a hard-core tracer particle (TP) performing a biased random walk in an adsorbed monolayer, composed of mobile hard-core particles undergoing continuous exchanges with a vapor phase. In terms of an approximate approach, based on the decoupling of the third-order correlation functions, we obtain the density profiles of the monolayer particles around the TP and derive the force-velocity relation, determining the TP terminal velocity, V_{tr}, as the function of the magnitude of external bias and other system's parameters. Asymptotic forms of the monolayer particles density profiles at large separations from the TP, and behavior of V_{tr} in the limit of small external bias are found explicitly.

  • 1. Laboratoire de Physique Théorique et Modèles Statistiques (LPTMS),
    CNRS : UMR8626 – Université Paris XI - Paris Sud
  • 2. Laboratoire de Physique Théorique des Liquides (LPTL),
    CNRS : UMR7600 – Université Paris VI - Pierre et Marie Curie
  • 3. Laboratoire de Physique de la Matière Condensée (LPMC),
    CNRS : UMR7125 – Collège de France