Diffusion of noninteracting particles into a semi-infinite lattice.

Consider a gas of noninteracting particles diffusing into a semi-infinite lattice, Z+×ZD−1, subject to exclusion of double occupancy. An exact closed set of equations can be obtained and solved (in closed form) for the single-site occupancies or densities. Equations for the n-site occupancies couple only to such functions for n and n-1 sites, as for an infinite lattice. Their analysis reveals that negative pair correlations develop during this process, reflecting the propensity for diffusion to reduce density inhomogeneities and fluctuations. Disciplines Condensed Matter Physics | Physics Comments This article is published as Evans, J. W. "Diffusion of noninteracting particles into a semi-infinite lattice." Physical Review B 41, no. 4 (1990): 2158, doi: 10.1103/PhysRevB.41.2158. Posted with permission. This article is available at Iowa State University Digital Repository: http://lib.dr.iastate.edu/physastro_pubs/424 PHYSICAL REVIE%' B VOLUME 41, NUMBER 4 1 FEBRUARY 1990 Diffusion of noninteracting particles into a semi-infinite lattice J. %. Evans Ames Laboratory and Departments of Mathematics and Physics, Iowa State University, Ames, Iowa 500II (Received 8 September 1989) Consider a gas of noninteracting particles diffusing into a semi-infinite lattice, Z+ XZ ', subject to exclusion of double occupancy. An exact closed set of equations can be obtained and solved (in closed form) for the single-site occupancies or densities. Equations for the n-site occupancies couple only to such functions for n and n —1 sites, as for an infinite lattice. Their analysis reveals that negative pair correlations develop during this process, reflecting the propensity for diffusion to reduce density inhomogeneities and fluctuations.