1 2 Se p 20 05 Edge spin accum ulation in sem iconductor tw o-dim ensionalhole gases

T he controlled generation oflocalized spin densities is a key enabler ofsem iconductor spintronics In this w ork,w e study spin H alle ect induced edge spin accum ulation in a tw o-dim ensionalhole gas w ith strong spin orbit interactions. W e argue that it is an intrinsic property, in the sense that it is independent of the strength of disorder scattering. W e show num erically that the spin polarization near the edge induced by this m echanism can be large,and that itbecom es larger and m ore strongly localized as the spin-orbit coupling strength increases,and is independent ofthe w idth ofthe conducting strip once this exceeds the elastic scattering m ean-free-path. O ur experim ents in tw o-dim ensionalhole gas m icrodevices con rm this rem arkable spin H alle ect phenom enology. A chieving com parable levels of spin polarization by external m agnetic elds w ould require laboratory equipm ent w hose physical dim ensions and operating electricalcurrents are m illion tim es larger than those ofour spin H alle ect devices.