Tunable spin polarization in a two-dimensional electron gas modulated by a ferromagnetic metal stripe and a Schottky metal stripe

Abstract

We report on a theoretical study of the spin-dependent electron transport in a two-dimensional electron gas (2DEG) modulated by a stripe of ferromagnetic metal and a stripe of Schottky metal in a parallel configuration. It is shown that a device consisting of a 2DEG and a single ferromagnetic metal stripe with magnetization parallel to the current direction possesses an intrinsic symmetry and does not give spin-polarized current. The symmetry is broken in the device with the double metal stripe structure. The spin-dependent transmission and conductance of the device are calculated. It is shown that highly spin-polarized electron transport can be achieved in this structure. It is also shown that the spin polarity of the electron transport can be switched by a voltage applied to the Schottky metal stripe. The underlying physical mechanism of the results is discussed in terms of spin-dependent tunneling process in the device.