Hall effect in the presence of strong spin-disorder scattering

The Hall mobility μH of a single hole in a Mott-Hubbard band of a magnetic insulator is considered using a path formulation of the atomic limit of the Hubbard model. It is shown that within a generalization of the retraceable-path approximation, the Hall mobility and the drift mobility μD are essentially equal at high temperatures compared with the bandwidth, but that the Hall mobility becomes small compared to the drift mobility as the temperature is lowered. The ratio μHμD becomes proportional to the ratio of the temperature to the bandwidth at low temperatures.