The spin–orbit interaction (SOI) in zincblende semiconductor quantum wells can be set to a symmetry point, in which spin decay is strongly suppressed for a helical spin mode. Here the diffusive evolution of a local spin excitation into a helical spin mode is mapped by a time-resolved and spatially resolved magneto-optical Kerr rotation technique.
M. P. Walser et al., Nature Physics 8, 757 (2012).
