Congratulations to Glade Sietsema for successfully defending his PhD dissertation on "Properties and Dynamics of Spin Waves in One and Two Dimensional Magnonic Crystals."

"Dr. Sietsema derived the properties of waves of magnetic distortion propagating in magnetic materials, including the propagating behavior of a wave pulse of magnetic distortion. He further derived the frequencies of magnetic waves in the presence of spatially-varying electric fields. These electric fields, in crystals which possess strong spin-orbit interaction, cause shifts in the magnetic wave velocity. As a result these spatially-varying electric fields open up frequency gaps in the spin-wave frequencies, preventing spin-waves of specific frequencies from propagating through the material."
— Michael Flatté, PhD advisor