2007/01/17 by S. Chesi, Chesi, S., G. F. Giuliani +1
Physics and Astronomy · #FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #cond-mat.mes-hall
paper · pdf · doi:10.48550/arxiv.cond-mat/0701415
arxiv created 2007/01/17 · arxiv updated 2009/12/01
Because of the peculiar coupling of spatial and spin degrees of freedom effected by the Rashba spin-orbit interaction, lateral confinement of a two dimensional electronic system leads to a finite transverse spin polarization near the longitudinal edges of a current carrying quantum wire. The sign of this component of the polarization is opposite at the two edges and can be reversed upon inversion of the current. Interestingly for small spin orbit coupling this is the largest contribution to the total polarization, its magnitude being of second order in the coupling constant. As a consequence this phenomenon cannot be revealed in lowest order perturbative approaches. An in plane spin polarization component is also present that is perpendicular to the current. Within the same model this component would be also present in the bulk. On the other hand while in the latter case its magnitude is linear in the coupling constant, we find that it only represents a third order effect in the wire geometry. Our results are consistent with a general rigorous argument on the parity of the components of the spin polarization with respect to the sign of the spin orbit coupling constant.