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Condensed Matter Seminar: “Coupled spin-charge dynamics in semiconductors: from Coulomb drag to spin Hall effect”

Event Type
190 Engineering Sciences Bldg - corner Goodwin & Springfield 
Dec 6, 2013   1:00 pm  
Giovanni Vignale, Department of Physics, University of Missouri-Columbia
Originating Calendar
Physics - Condensed Matter Seminar

The recently acquired capability to excite transient spin and electron-hole density gratings in semiconductors quantum wells and monitor their evolution in real time opens new avenues to the study of coupled spin-charge dynamics of electrons in semiconductors.

In this talk I describe some of the physical effects that have been recently observed by this technique: the spin Coulomb drag, the electron-hole Coulomb drag, and the anomalous drift and diffusion caused by spin-orbit interactions. I then discuss a recent theoretical prediction that an electric field  parallel to the wavefronts of an electron-hole grating in a GaAs quantum well generates, via the electronic spin Hall effect, a spin grating.  A detailed study of the coupled spin-charge dynamics for quantum wells grown in different directions reveals rich features, including the possibility of generating a helical spin grating from a density grating.

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