Physics (Internal)

Investigating Heat and Spin Transport with Inelastic Light Scattering

This event is part of the Biophysics/Condensed Matter Seminar Series.

Many transport phenomena arise from a nonequilibrium between carriers. For example, heat transport in semiconductors is limited by an energy transfer bottleneck and nonequilibrium between optical phonons and acoustic phonons. In magnetic insulators, a thermal nonequilibrium between the phonons and the spin carriers (spin waves) generates a pure spin current, the main quantity of interest in spintronic devices. Inelastic light scattering is one of the few techniques capable of differentiating between these carriers. Both Raman and Brillouin light are used to investigate optical and acoustic phonon temperatures in silicon. Brillouin light scattering is used examine a thermal nonequilibrium between phonons and spin waves, ultimately allowing for the thermally generated spin current to be measured. These results open up new possibilities for characterizing the intrinsic ability of a material in generate a spin current.