DIFFUSION OF ELECTRONS IN 2-DIMENSIONAL DISORDERED SYMPLECTIC SYSTEMS

Diffusion of electrons in two-dimensional disordered systems with spin -orbit interactions is investigated numerically. Asymptotic behaviors of the second moment of the wave packet and of the temporal autocorrel ation function are examined. At the critical point, the autocorrelatio n function exhibits the power-law decay with a nonconventional exponen t alpha, which is related to the fractal structure in the energy spect rum and in the wave functions. In the metallic regime, the present res ults imply that transport properties can be described by the diffusion equation for normal metals.