Extrinsically vs. intrinsically driven spin Hall effect in disordered mesoscopic multiterminal barsB. K. Nikolic and L. P. Zârbo
Department of Physics and Astronomy, University of Delaware - Newark, DE 19716-2570, USA
received 7 November 2006; accepted in final form 21 December 2006; published February 2007
published online 12 February 2007
We show that pure spin Hall current, flowing out of a four-terminal two-dimensional electron gas (2DEG) within inversion asymmetric heterostructure, contains contributions from both the extrinsic mechanisms (spin-orbit-dependent scattering off impurities) and the intrinsic ones (due to the Rashba coupling). The extrinsic contribution vanishes in the weakly and strongly disordered limits, and the intrinsic one dominates in the quasiballistic limit. However, in the crossover transport regime the spin Hall conductance is not simply reducible to either of the two mechanisms, which can be relevant for interpretation of experiments on dirty 2DEGs (SIH V. et al., Nature Phys., 1 (2005) 31). We also predict sample-to-sample mesoscopic fluctuations, and even sign change, of both the spin Hall conductance and the applied voltages to transverse terminals (ensuring that spin Hall current outflowing through them is pure with no accompanied net charge current) in phase-coherent bars.
72.25.Dc - Spin polarized transport in semiconductors.
73.63.-b - Electronic transport in nanoscale materials and structures.
© Europhysics Letters Association 2007