The spin-orbit interaction for controlling various spin states
The coupling of spin and motion mediated by the spin-orbit interaction can provide a bi-lateral access of these two quantities - spin & motion (or transport), of electrons. As a result, the spin-orbit interaction can empower us to control electron spins through electric excitations - it seems we have better controllabilities of charge than spin as history explains. Electrons in a crystal with broken inversion symmetry experience different energy levels determined by the directions of both motion and spin. Controlling the motional component (by applying a current through), we can therefore access to the electron spin population. This is a current-induced spin polarisation and if one does this in ferromagnetic materials, you can also control the localised electron spins that is hardly susceptible to applying a current - that's why they are called "localised". We are in part of an active international research collaboration (with many world-leading researchers in the world), and attempt to understand the microscopic pictures of current-induced spin polarisation and mangetisation control, in as view of harnessing for technology. Some details of this would be found in the following papers.
- "An anti-damping spin-orbit torque originating from the Berry curvature", Nature Nanotechnology 9 211 (2014)
- "Spin-orbit-driven ferromagnetic resonance", Nature Nanotechnology 6 413 (2011).