Spin Torque with Point Contacts: Generating Nonlinear Waves with Magnetic Media in a Localized Way
Spin torque offers new means to locally excite nonlinear dynamics in magnets. Possible applications include oscillators, disk drive heads, and non-volatile memory. Theoretical analysis is made challenging by the inherent difficulties of stiff differential equations with non-local terms. Originally formulated in 1999, analysis of the nonlinear Landau-Lifshitz-Slonczewski equation has proceeded either by perturbative amplitude expansion or brute force micromagnetic simulations. I will survey the current state-of-the-art, with and emphasis on efforts to accelerate simulation algorithms for infinite domains, and analysis of a novel magnetic excitation: the magnon 'droplet'.
Tom Silva, National Institute of Standards and Technology