Proximity Effects of a Symmetry-Breaking Interface on Spins of Photoexcited Electrons

摘要

We study reflection of optically spin-oriented hot electrons as a means to probe the semiconductor crystal symmetry and its intimate relation with the spin-orbit coupling. The symmetry breaking by reflection manifests itself by tipping the net-spin vector of the photoexcited electrons out of the light propagation direction. The tipping angle and the pointing direction of the net-spin vector are set by the crystal-induced spin precession, momentum alignment, and spin-momentum correlation of the initial photoexcited electron population. We examine nonmagnetic semiconductor heterostructures and semiconductor-ferromagnet systems and show the unique signatures of these effects.