title: Nondiffusive spin dynamics in a two-dimensional electron gas.
abstract: We describe measurements of spin dynamics in the two-dimensional electron gas in GaAs/GaAlAs quantum wells. Optical techniques, including transient spin-grating spectroscopy, are used to probe the relaxation rates of spin polarization waves in the wave vector range from zero to 6x10(4) cm-1. We find that the spin polarization lifetime is maximal at a nonzero wave vector, in contrast with expectations based on ordinary spin diffusion, but in quantitative agreement with recent theories that treat diffusion in the presence of spin-orbit coupling.
authors.affiliation: Physics Department, University of California, Berkeley and Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: C P
authors.initials: CP
authors.lastname: Weber
authors.forename: J
authors.initials: J
authors.lastname: Orenstein
authors.forename: B Andrei
authors.initials: BA
authors.lastname: Bernevig
authors.forename: Shou-Cheng
authors.initials: SC
authors.lastname: Zhang
authors.forename: Jason
authors.initials: J
authors.lastname: Stephens
authors.forename: D D
authors.initials: DD
authors.lastname: Awschalom