Electric field effect on the magnetic properties of III-V ferromagnetic semiconductor (In, Mn)As and ((Al),Ga,Mn)As

We have investigated the magnetotransport properties of field-effect transistors (FET) having a III-V ferromagnetic semiconductor channel layer. One can control not only the ferromagnetic transition temperature T-C but also the magnetization and the coercive force of (In,Mn) As channel layers isothermally and reversibly by gate electric fields. A small change of the magnetization upon application of gate electric fields is also observed in FETs with a (Ga,Mn) As channel. Results on a (Al,Ga,Mn) As channel FET are also presented.