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Fall Seminar Series
Presentation by:
Chris Weber
Lawrence Berkeley National Laboratory
Title:
Spin-orbit interaction and the search for the persistent spin helix
Abstract:
The spin-orbit interaction is a relativistic effect: an electron moving
in an external electric field sees a magnetic field in its rest frame.
In a semiconductor the interaction causes an electron's spin to precess
as it moves through the material; this is the basis of various proposed
"spintronic" devices. In nano-structures, quantum confinement can change
the symmetry of the spin-orbit interaction; under special circumstances
a new, higher symmetry is predicted to create a conserved, helical spin
wave at a wavelength of a few microns: the "persistent spin helix"
(PSH). I describe optical experiments to measure this effect in
semiconductor quantum wells. I describe the first evidence of a
nearly-PSH state, and progress toward realizing the PSH state.
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