Flutuações universais da condutância de Spin-Hall em uma cavidade caótica de Dirac

Abstract

Throughout the latest years, the interest on Spintronics has increased. The principal purposes of the eld are to detect, manipulate, create and polarize spin currents. Within this topic, it is possible to emphasize the Spin Hall E ect(SEH) and the Inverse Spin Hall E ect(ISEH). In this dissertation, we analytically investigate the universal fluctuation of the conductance of the spin in a chaotic quantum point with chiral symmetry at low temperatures. We used random matrices theory and the expansion of the diagrammatic method for that purpose. We showed that when the chirality is broken, the universal fluctuation of the conductance dispersion is in the order of rms hGf sHi 0:18e=4 and that when there is the preservation of the chiral symmetry, the universal fluctuation of the conductance dispersion occurs in the order of rms [GqsH] 0:283e=4 which coincides with the literature. We also worked on ISEH, through the analytical analysis with the semi-classic expansion of the conductance and showed that in the semi-classic limit the relation rms [GqsH] = p2 rms hGf sHi is valid.