Local spin polarization in a quantum wire induced by the Rashba interaction

A local spin–orbit (SO) interaction of Rashba type induces the appearance of a static spin distribution in a quantum wire when a steady current is flowing along the wire. We obtain the density and spin distributions using matching of the wireʹs propagating and evanescent modes at the SO interfaces. A nonvanishing net spin lying in the two-dimensional (2D) wire plane and pointing perpendicularly to the wire is obtained. The relevance of the wireʹs evanescent modes is stressed.