Spin Splitting and Spin Current in Strained Bulk Semiconductors

We present a theory for two recent experiments in bulk strained semiconductors \cite{kato1, kato2} and show that a new, previously overlooked, strain spin-orbit coupling term may play a fundamental role. We propose simple experiments that could clarify the origin of strain-induced spin-orbit coupling terms in inversion asymmetric semiconductors. We predict that a uniform magnetization parallel to the electric field will be induced in the samples studied in \cite{kato1, kato2} for specific directions of the applied electric field. We also propose special geometries to detect spin currents in strained semiconductors.