Regensburg 2007 – scientific programme

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DY: Fachverband Dynamik und Statistische Physik

DY 16: Brownian motion and transport I

DY 16.2: Talk

Tuesday, March 27, 2007, 14:45–15:00, H3

Traffic phenomena in driven transport with internal states — •Tobias Reichenbach, Thomas Franosch, and Erwin Frey — Arnold Sommerfeld Center for Theoretical Physics (ASC) and Center for NanoScience (CeNS), Department of Physics, Ludwig-Maximilians-Universität München, Theresienstrasse 37, D-80333 München

Traffic phenomena occur in biological contexts as well as in mesoscopic quantum systems. Molecular motors move along parallel one-dimensional filaments in cells, serving as biological engines. On the other hand, spintronic devices aim to exploit quantum effects, the spin of electrons, when passing these trough nanowires. Here, we present a generic model that underlies both situations [1]. Allowing particles in an exclusion process to possess internal states, the latter account for several parallel lanes as well as different spin states, where Pauli’s exclusion principle is respected. Exploring the system’s behavior, we find that it can be tuned by controlling the particle fluxes at the boundaries. In particular, a spontaneous polarization may occur at a certain spatial position and, upon changing the fluxes at the boundaries, be driven in or out of the system. We derive the shape of the density profiles as well as resulting phase diagrams analytically by a mean-field approximation and a continuum limit.

[1] T. Reichenbach, T. Franosch, E. Frey, Phys. Rev. Lett. 97, 050603 (2006)