{
  "id": "cond-mat/0412626",
  "version": "v3",
  "published": "2004-12-22T15:45:00.000Z",
  "updated": "2005-09-14T09:15:55.000Z",
  "title": "Asymmetric Diffusion",
  "authors": [
    "Norman Packard",
    "Rob Shaw"
  ],
  "comment": "17 pages, 8 figures v3: one additional figure, several additional references, conceptually unchanged",
  "categories": [
    "cond-mat.stat-mech"
  ],
  "abstract": "Diffusion rates through a membrane can be asymmetric, if the diffusing particles are spatially extended and the pores in the membrane have asymmetric structure. This phenomenon is demonstrated here via a deterministic simulation of a two-species hard-disk gas, and via simulations of two species in Brownian motion, diffusing through a membrane that is permeable to one species but not the other. In its extreme form, this effect will rapidly seal off flow in one direction through a membrane, while allowing free flow in the other direction. The system thus relaxes to disequilibrium, with very different densities of the permeable species on each side of the membrane. A single species of appropriately shaped particles will exhibit the same effect when diffusing through appropriately shaped pores. We hypothesize that purely geometric effects discussed here may play a role in common biological contexts such as membrane ion channels.",
  "revisions": [
    {
      "version": "v3",
      "updated": "2005-09-14T09:15:55.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "asymmetric diffusion",
      "membrane ion channels",
      "two-species hard-disk gas",
      "asymmetric structure",
      "common biological contexts"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 17,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}