Description

2011/10/13, Roland Winkler (Northern Illinois University and Argonne National Laboratory, USA/ IKERBASQUE FELLOW)
Place:   Salón de Grados ZTF-FCT
Time:   11h.
Title:    Spinning Electrons
Abstract
Spin-orbit coupling makes the electron's spin degree of freedom respond to its orbital environment. Thus it gives us a "control knob" with which we can steer the purely quantum-mechanical spin degree of freedom. Recently, the electron's spin and spin-orbit coupling have attracted much attention due to the possibility to complement conventional charge-based electronics by novel approaches that use also the electron's spin ("spintronics").

In my talk I will provide a general introduction into the world of spinning electrons, followed by the discussion of a few examples for the rich and fascinating physics that emerges from the interplay between the spin and orbital dynamics of electrons in solids. Similar to an external magnetic field, spin-orbit coupling can give rise to spin precession. I will show how the precessional spin dynamics plays a central role for several rather different phenomena. For example, it can be used to generate a spin density (spin polarization) and a spin current (a flow of spin angular momentum even in the absence of a charge current). Furthermore, it can be used to manipulate spins. Yet it also gives rise to spin elaxation, i.e., the often unwanted yet unavoidable process that makes a nonequilibrium spin polarization disappear again.