Multiple switching of spin polarization injected into a semiconductor by a multiferroic tunneling junction

Abstract

A method for switching between multiple spin polarization of the electric current injected into a semiconductor is proposed, based on injecting spins from a diluted magnetic semiconductor through a multiferroic tunnel barrier. We show that it is important to combine a diluted magnetic semiconductor electrode with a multiferroic barrier to realize multiple switching of spin polarization on wide range. The reversal of either electric polarization or magnetization in a multiferroic barrier results in a sizable change in the spin polarization of the injected current both in magnitude and in sign, thereby providing a four-state electrical control of spin polarization. The electroresistance and electromagnetoresistance effects can be also realized in this structure. Our investigations may stimulate experimental studies of the multiferroic tunnel junctions.