JOINT SEMINAR WITH NORTHWESTERN UNIVERSITY
DIPOLE AND EXCHANGE SPIN WAVES IN YTTRIUM IRON GARNET FILMS
Speaker:
Prof. J. B. Ketterson
Northwestern University
Date: Monday, 11 March 2024
Time: 11:00 a.m.
Location: Bldg. 6/Room 125
Abstract:
Ferromagnetic films driven at microwave frequencies can support multiple kinds of propagating magnetic modes involving an inhomogeneous precession of the internal magnetization, commonly called spin waves. When the precession is uniform we have the well-known ferromagnetic resonance (FMR) phenomenon, the frequency of which involves the sample geometry and internal magnetization together with the external field and its direction. At small wavevectors the shift in precession frequency is dominated by the accompanying inhomogeneity of the internal magnetization (the so-called dipole field) and involves two kinds of waves, volume and surface, depending on the sample and magnetic field geometry. At larger wavevectors the dispersion is dominated by the exchange interaction. We will describe a series of experiments that probe and connect these various regimes.
Biography:
Professor got his PhD from University of Chicago, he was appointed Professor of Physics at the Physics Department of Northwestern University from 1974-present, he was chairman of physics department, acting associate and senior physicist and consultant at Argon National Laboratory for a long period. Associate editor of Applied Physics Letters, Divisional Editor of Cond. Mat. Phys., PRL,…
Had more than 50 PhD students the last of which is our student Luhaibi. His Research interests are: Superconducting materials and devices, thin film growth by MBE, Patterned nanostructure, nonlinear optics, heavy fermions, tunnelling, magnetic forces and novel-optical microscopy.
Synergistic activities:
(a) Writing and editing books
(b) Developing Specialized Courses
(c) Helping high school student with science fair projects.
All faculty, researchers and students are invited to attend.