Electrical control of carriers' spin orientation in the FeVTiSi Heusler alloy

Abstract

The direct control of carrier spin by an electric field at room temperature is one of the most important challenges in the field of spintronics. For this purpose, we here propose a quaternary Heusler alloy FeVTiSi. Based on first principles calculations, the FeVTiSi alloy is found to be an intrinsic bipolar magnetic semiconductor in which the valence band and conduction band approach the Fermi level through opposite spin channels. Thus the FeVTiSi alloy can conduct completely spin-polarized currents with a tunable spin-polarization direction simply by applying a gate voltage. Furthermore, by Monte Carlo simulations based on the classical Heisenberg Hamiltonian, the Curie temperature of the FeVTiSi alloy is predicted to be well above the room temperature. The bipolar magnetic semiconducting character and the room temperature magnetic ordering endow the FeVTiSi alloy with great potential for developing electrically controllable spintronic devices working at room temperature.