Quasiclassical Description of Transport Properties in Mesoscopic and Nanoscopic Systems
Ulrich Eckern and Peter Schwab
Physikalisches Institut, Augsburg Universitaet, 86135 Augsburg, Germany
Quasiclassical methods, developed several years ago and used successfully to describe non-equilibrium states in superconductors and superfluids (see, e.g., [1]), have recently been extended to meso- and nanoscopic systems. Within this approach, it is possible to study the influence of disorder and Coulomb interaction on the same footing [2], which is manageable since the method works on an intermediate level: microscopic details of the wave-functions, on the scale of the interatomic distance, are integrated out, leaving equations of motion which can be solved with sufficient accuracy. However, the boundary conditions necessary to include finite-size effects and, e.g., interface roughness [3], introduce non-linearities which at present are not well understood, in particular, when a realistic treatment becomes mandatory to understand the subtle effects observed in experiments. – This talk will give an overview on recent progress, with focus on spin-effects and spatial confinement, e.g., concerning the spin-Hall effect in a 2-D electron gas [4], and spin relaxation in narrow wires in the presence of spin-orbit coupling [5].

[1] U. Eckern and A. Schmid, J. Low Temp. Phys. 45, 137 (1981).
[2] P. Schwab and R. Raimondi, Ann. Phys. (Leipzig) 12, 471 (2003).
[3] T. Lück and U. Eckern, J. Phys.: Condens. Matter 16, 2071 (2004).
[4] R. Raimondi et al., preprint (2006), cond-mat/0601525.
[5] P. Schwab et al., preprint (2006), cond-mat/0606209.