Quantum size effect in an electron-spin filter based on hybrid ferromagnetic and semiconductor nanosystem

An electron-spin filter with a considerable spin polarization, based on the hybrid ferromagnetic (FM) and semiconductor nanosystem, was proposed very recently. In this work, we theoretically investigate the FM effect on the spin filtering of this device. It is shown that the degree of electron-spin polarization depends greatly on the sizes and position of the FM stripe. Thus, a quantum size effect exists in this device, and the optimal spin filtering effect can be achieved by properly fabricating the FM stripe.