Effective diffusion constant in a twodimensional medium of charged point scatterers
Abstract
We obtain exact results for the effective diffusion constant of a twodimensional Langevin tracer particle in the force field generated by charged point scatterers with quenched positions. We show that if the point scatterers have a screened Coulomb (Yukawa) potential and are uniformly and independently distributed then the effective diffusion constant obeys the VolgelFulcherTammann law where it vanishes. Exact results are also obtained for pure Coulomb scatterers frozen in an equilibrium configuration of the same temperature as that of the tracer.
 Publication:

Journal of Physics A Mathematical General
 Pub Date:
 February 2004
 DOI:
 10.1088/03054470/37/6/005
 arXiv:
 arXiv:condmat/0311125
 Bibcode:
 2004JPhA...37.2039D
 Keywords:

 Condensed Matter  Disordered Systems and Neural Networks;
 Condensed Matter  Statistical Mechanics
 EPrint:
 9 pages IOP LaTex, no figures