|
|
第８回ＣＯＥ(自己組織系物理)セミナー (通算13回)
| “Tracer diffusion in hard-core lattice gases: Einstein relation verified” |
| 講 師 |
Gleb OSHANIN
（Laboratoire Physique Théorique des Liquides Université Pierre et Marie Curie, フランス、専任研究員） |
| 日 時 |
2004年11月22日（月） 13:15-14:15pm |
| 場 所 |
早稲田大学理工学部62W号館1階中会議室 |
| 講演の概要 |
In this presentation, we overview some recent results on biased tracer diffusion in lattice gases. We consider both models in which the gas particles density is explicitly conserved and situations in which the lattice gas particles undergo continuous exchanges with a reservoir, which is appropriate, e.g., to adsorbed monolayers in contact with the vapor phase. For all these models we determine, in some cases exactly and in other ones - using a certain decoupling approximation, the mean displacement of a tracer particle driven by a constant external force in a dynamical background formed by the lattice gas particles.
Evaluating the tracer particle mean displacement explicitly we are able to define the tracer mobility, which allows us to demonstrate that the Einstein relation between the tracer mobility and the diffusivity generally holds, despite the fact that in some cases diffusion is anomalous. For models treated within the decoupling approximation, our analytical results are confirmed by Monte Carlo simulations.
Perturbances of the lattice gas due to the presence of a driven tracer particle and the form of the density profiles are also discussed.
|
| 紹介教員 |
田崎秀一 |
|
 |
