Robust Pathway for Voltage Controlled Switching of Ferromagnets Via an Intermediate Skyrmion State

Traditional voltage control of magnetic anisotropy can be used to reverse the magnetization of a perpendicular nanomagnet by utilizing magnetization precession around a bias magnetic field. This is energy efficient as electric field is used instead of spin current but suffer from switching error due to incoherence in the presence of defects[1]. We show with extensive micromagnetic simulation that the presence of Dzyaloshinskii-Moriya Interaction can drive the magnetization through an intermediate skyrmionic state while switching between two stable perpendicular states thereby avoiding precessional magnetization dynamics as well as the need for a bias magnetic field[2]. We investigate the switching physics that involves alternative skyrmion mediated pathway in detail in the presence of thermal noise, defects and perturbative spin current. We show our proposed mechanism leads to extremely low error switching while also being potentially 2 orders of magnitude more energy efficient than state of the art spin transfer torque based switching.
1. Grezes et al IEEE Magnetics Letters 8, 3102705 (2017)
2. Bhattacharya et al arXiv 1707.07777 (2017)