The Center for Emergent Materials Winter Colloquium will be Wednesday, March 3, 2010 from 4-5pm in the Smith Seminar Room, Physics Research Building.
Prof. Ian Appelbaum, University of Maryland. presents “Lateral Spin Transport and Electrostatic Gating in Silicon.”
Abstract:
Silicon, the materials basis for most semiconductor electronics devices, has been known for decades to have an extraordinarily long spin lifetime. Using unique spin-polarized hot-electron injection and detection techniques, we have observed unprecedented spin coherence, and extracted very long spin lifetimes of conduction electrons traveling over macroscopic distances, even in the millimeter range. In this talk, I will discuss our recent work on lateral spin transport devices where a buried SiO2 native oxide serves as a gate dielectric to electrostatically control the proximity of spin-polarized conduction electrons to the interface. Lattice inversion symmetry breaking, and/or coupling to paramagnetic defects, drastically affects the spin lifetime, as can be seen from time-of-flight distributions extracted from spin precession measurements. Effects seen in high magnetic fields further elucidate the mechanisms relevant to electron spin relaxation at this technologically important electronic interface. Continue reading →