Theory of spin-polarized transport in semiconductor heterojunctions: Proposal for spin injection and detection in silicon

摘要

Spin injection and detection in silicon is a difficult problem, in partbecause the weak spin-orbit coupling and indirect gap preclude using standardoptical techniques. We propose two ways to overcome this difficulty, andillustrate their operation by developing a model for spin-polarized transportacross a heterojunction. We find that equilibrium spin polarization of holesleads to a strong modification of the spin and charge dynamics of electrons,and we show how the symmetry properties of the charge current can be exploitedto detect spin injection in silicon using currently available techniques.