Enhanced spin injection and magnetoconductance by controllable Rashba coupling in a ferromagnet/two-dimensional electron gas structure

Abstract

In this letter, a new hybrid structure, which comprises of a ferromagnet (FM) deposited on a two-dimensional electron gas (2DEG), is proposed. We present numerical calculations of the ballistic spin-dependent transport properties of the structure in the presence of spin-orbit coupling as described by the Rashba Hamiltonian. It is shown that the gate electrode on top of the structure can be used to control the Rashba coupling and hence the spin injection in the 2DEG. For the typical InAs system assumed in our numerical calculations, the spin polarization in the 2DEG reaches a ratio of up to ∼90%. The structure is also predicted to show magnetoconductance behaviour upon switching the magnetization direction of the FM stripe. The large spin polarization and MC of the proposed structure demonstrate the potential of the device as a spin injector in spin-logic devices as well as a magnetic sensor with ultra-high density storage.