Interaction of magnetization and heat dynamics for pulsed domain wall movement with Joule heating

摘要

Pulsed domain wall movement is studied here in Ni_(80)Fe_(20) nanowires on SiO_2, using a fully integrated electrostatic, thermoelectric, and micromagnetics solver based on the Landau-Lifshitz-Bloch equation, including Joule heating, anisotropic magneto-resistance, and Oersted field contributions. During the applied pulse, the anisotropic magneto-resistance of the domain wall generates a dynamic heat gradient, which increases the current-driven velocity by up to 15%. Using a temperature-dependent conductivity, significant differences are found between the constant voltage-pulsed and constant current-pulsed domain wall movement: constant voltage pulses are shown to be more efficient at displacing domain walls whilst minimizing the increase in temperature, with the total domain wall displacement achieved over a fixed pulse duration having a maximum with respect to the driving pulse strength.