The photo-voltaic effect refers to the creation of an electric voltage in a material upon exposure to light. This presentation reports the discovery of a photo-spin-voltaic effect, in which photons induce a spin voltage in a nonmagnetic metal that is in proximity to a magnetic insulator. This discovery offers a very easy yet effective approach for the generation and manipulation of pure spin currents and thereby has significant implications for the future development of spin electronics. The experiments used platinum (Pt)/magnetic insulator (MI) bi-layered structures. Upon exposure to light, there occurs photon-driven, spin-dependent excitation of electrons in several Pt atomic layers near the Pt/MI interface. Such excitation gives rise to a spin voltage at the interface and a corresponding pure spin current that flows across the Pt thickness. Via spin-orbit coupling, the spin current produces an electric voltage across one of the lateral dimensions of the Pt layer.
For further information please contact haujian.liu [at] nist.gov (Jason Liu), 301-975-8144; haujian.liu [at] nist.gov (haujian[dot]liu[at]nist[dot]gov)