  Quantum transport in disordered ferromagnetic (III,Mn)V semiconductors is
studied theoretically. Mesoscopic wires exhibit an Anderson disorder-induced
metal-insulator transition that can be controlled by a weak external magnetic
field. This metal-insulator transition should also occur in other materials
with large anisotropic magneto resistance effects. The transition can be useful
for studies of zero-temperature quantum critical phase transitions and
fundamental material properties.
