SCATTERING APPROACH TO QUANTUM TRANSPORT - TOWARD A CONSISTENT PHYSICAL PICTURE

Quantum transport in disordered systems can be studied via the transfer matrix M. In a previous paper, the statistical distribution of M at the mesoscopic level was constructed from single-scattering units. The assumption of "isotropy," that restricted the model to certain observables for quasi-1D systems, is relaxed in this Letter. The new limiting distribution satisfies a diffusion equation, is universal, specified by the mean free paths between all pairs of channels, and is insensitive to other microscopic details. Results for the ballistic, metallic, and localized regimes are promising.