Spin-dependent transmission through a Rashba spin-split system with ferromagnet contacts

We study theoretically the conductance modulation through a Rashba-like quantum waveguide connected to two ferromagnet contacts based on quantum waveguide method. In this waveguide, the spin precession together with multiply reflection interference dominants the behaviors of the conductance resonance. Under the single mode approximation, the conductance exhibits periodially sharp resonant peaks with varing the length of the Rashba semiconductor, when the phase shifts of the spin-down and -up components are mπ/2mπ/2 (m an integer), respectively, and their phase difference is mπ. For a periodic waveguide with normal metals, the modulation of the multiply reflected wave can also control the transmission. Besides, the influence of the spin polarization in the ferromagnet contacts on the conductance is examined in detail.