Magnetoresistance and Hall effect in the ferromagnetic semiconductor Ga1−xMnxAs

The resistivity, temperature, and magnetic field dependence of the anomalous Hall effect in a series of metallic Ga1−xMnxAs thin films with x=0.015 to 0.08 is presented. A quadratic dependence of the anomalous Hall resistance on the resistivity is observed, with a magnitude which is in agreement with Berry phase theories of the anomalous Hall effect in dilute magnetic semiconductors.