Physics and Astronomy Calendar

Magnetoresistive heterostructures have important applications in magnetic storage technology and spintronics. This thesis uses Green’s function techniques to calculate the transport properties of a novel structure Fe/Ag/Fe/InAs/Ag. We show that the magnetoresistance can be enhanced to above 1000% due to the wave-vector filtering effect imposed by the InAs layer; meanwhile, the resistance-area product is as low as ~10Ωµm^2. The magnetoresistance shows oscillations with the InAs thickness when the Fermi level is in the conduction band, and the oscillations are quantitatively explained by theory.
Heat-assisted magnetic recording (HAMR) is a leading technology for the next-generation magnetic data storage. This thesis uses micromagnetic simulations to study magnetization transition shifts induced by nonequilibrium spin dynamics in HAMR. We examine the effects of thermal profile, head velocity, damping, and head field rise-time. We also propose methods to determine spin temperature and its lag relative to lattice temperature. By quantifying switching time, spin temperature lag, and superparamagnetic writing, we show that superparamagnetic effects cause largest transition shifts and dominate in typical HAMR processes.