| title: | Dynamics of generalized Brownian particles in quasiperiodic nonlinear media |
|---|---|
| reg no: | ETF5662 |
| project type: | Estonian Science Foundation research grant |
| subject: |
1.1-1.5. Exact Sciences |
| status: | completed |
| institution: | TU Faculty of Physics and Chemistry |
| head of project: | Risto Tammelo |
| duration: | 01.01.2003 - 31.12.2005 |
| description: | It is intended to investigate the diffusion of Brownian particles on tilted piecewise linear potentials and in models with non-periodic boundary conditions with the aim to establish: (i) the agents facilitating the amplification of diffusion and influencing the character of amplification, (ii) the coherence properties of motion of Brownian particles on tilted periodic structures, and (iii) the influence of the boundaries of the periodic potentials on the effect of amplification of diffusion. The expected results are the following. On non-harmonic potentials a significant enhancement of the amplification effect of diffusion may take place depending on the symmetry properties of the potential. On a potential with several local minima per period the structure of the amplified diffusion coefficient will probably be more complicated, having several maximums. It is expected that the coherence properties of the motion of particles rely on the existence of two different channels, a passive and an active one, of growth of diffusion. The passive one is caused by delocalization of particles by tilting, whereas the active channel is due to the interaction of the potential and the current, which is significant within a certain critical range of tilting where the statistical properties of the system may change. It is the active channel within which the amplification of the diffusion with respect to free diffusion takes place. For non-periodic boundary conditions we expect that the dependence of the diffusion coefficient on the tilting is different for different choices of the end points of the potential. In this case the tilting may cause either the amplification or suppression of the diffusion. |
| project group | ||||
|---|---|---|---|---|
| no | name | institution | position | |
| 1. | Dmitri Martila | University of Tartu | doctoral student | |
| 2. | Risto Tammelo | TU Faculty of Physics and Chemistry | Prof., Head of Inst. | |
| 3. | Teet Örd | University of Tartu | Assoc. Prof. | |