Low-voltage control of ferromagnetism in a semiconductor p-n junction

Controlling the magnetization by low-voltage charge depletion in field-effect transistors has been a formidable challenge due to the typically large carrier concentrations in ferromagnets compared to semiconductors. Here we demonstrate that this concept is viable in an all-semiconductor, p-n junction transistor utilizing a thin-film ferromagnetic (Ga, Mn) As channel. We report gate-dependent Curie temperature and magnetoresistance, and persistent magnetization switchings induced by short electrical pulses of a few volts.