Condensed Matter Seminar Announcement Prof. D.N. Sheng CSU, Northridge " Spin Hall Effects in Disordered Spin-Orbit Coupling Electron Systems " Date: Thursday, May 26, 2005 Time: 4:10 pm 416 Physics/Geology Abstract: The recent proposals of intrinsic spin Hall effect (SHE) in spin-orbit coupling systems have generated strong interest as well as debate. In this talk I will first present our recent numerical studies in 2D Rashba model. Based on a finite-size scaling analysis, it is shown that the spin Hall conductance vanishes in the Rashba model once the disorder is turned on. In particular, the Laughlin’s gauge argument is performed numerically, which unambiguously demonstrates a zero spin transfer between two open edges of the sample during an adiabatic insertion of a flux quantum in the presence of disorder, in contrast to the integer quantum Hall effect. The general implication of our numerical results on intrinsic SHE of different models will be discussed. Finally, I will also demonstrate evidences for a topological spin Hall insulator in a different model first proposed by Haldane for two dimensional graphene, and its distinct behavior from other systems proposed for the intrinsic SHE.

E-Mail: donna.sheng1@csun.edu
Web Page: http://www.csun.edu