Universalities In Scattering On Mesoscopic Obstacles In Two-Dimensional Electron Gases

Scattering of electrons propagating through a disordered conductor is studied for the case when the scatterers are large compared the de Broglie wavelength of electrons but small compared the electron mean free path. If such randomly located and oriented mesoscopic scatterers are of an arbitrary convex shape, electron scattering has a universal feature: the ratio of the “quantum” (total) to transport scattering rates ŋ = T_tr/T_q does not depend on the shape of the scatterer but only on the nature of scattering (specular vs. diffuse) and on the spatial dimensionality. In particular, for specular scattering in two-dimensional (2D) electron gas ŋ = 3/2. Possible experimental manifestations of this universality are discussed.