Spin Wave Model to study multilayered magnetic materials Sarah McIntyre
Why study spin waves? Atomic level precision materials Well defined interfaces Magnetic properties of buried interfaces difficult to measure Probe via spin waves
Ferromagnetism Spins align parallel Exchange interaction Resultant magnetic field Low anisotropy
Antiferromagnetism Spins align antiparallel Not net magnetic field High anisotropy
Ferromagnetic resonance mode
Excited modes
Model Lattice
Hamiltonian
Equations of motion Commutators of the Hamiltonian; Assume plane wave solution;
Dipole sums Slow to converge
Dipole sums Rapidly convergent form
Mode Profiles in a Ferromagnetic Film
Multilayers
Pinning of the FMR mode
Frequency shifts due to an interface
Future Work Fine tuning experimental parameters Fit to data sets from experiment Value for exchange at the interface?