Inverse engineering and composite pulses for magnetization reversal

Abstract

We put forward a method for achieving fast and robust for magnetization reversal in a nanomagnet, by combining the inverse engineering and composite pulses. The magnetic fields, generated by microwave with time-dependent frequency, are first designed inversely within short operation time, and composite pulses are further incorporated to improve the fidelity through reducing the effect of magnetic anisotropy. The high-fidelity magnetization reversals are illustrated with numerical examples, and visualized on Bloch sphere. The influence of damping parameters, relevant to the pulse sequence, is finally discussed based on Landau-Lifshitz-Gilber equation. These results pave the way for precise but fast magnetization reversal or switching, with the applications in high density information storage and processing.