Electron transport at the Anderson transition

The low-temperature behavior of transport properties across an Anderson-type metal-insulator transition is considered. It is shown that previous discussions are flawed; in particular, we demonstrate that the thermopower S is not divergent as the mobility edge Ec is approached from the metallic side. At Ec, S achieves a temperature-independent value, determined solely by the conductivity index {ν}. Furthermore, far from being universal in the metallic phase, the Lorentz number changes as the mobility edge is approached and, in addition, depends on {ν}. We also prove that, contrary to previous assertions, the thermal conductivity varies like T^ν+1 as T{→}0.