Perpendicular magnetic anisotropy tilting for spin–orbit torque-induced field-free switching of magnetization

Abstract

Since the discovery of spin–orbit torque, it has garnered significant attention as one of potential spintronics building blocks, owing to its distinct advantages, such as fast switching capabilities. For the practical application of spin–orbit torque, several technical challenges remain; a primary one being the elimination of the necessity for an external magnetic field during switching process. To address this issue, here, we thoroughly explore the nature of perpendicular magnetic anisotropy tilting via wedge sputtering deposition incorporating a physical barrier. We precisely quantify the tilted angle of magnetic anisotropy, and introduce a way to determine the direction of the magnetic anisotropy tilting. In addition, the realization of field-free magnetization switching using the tilted perpendicular magnetic anisotropy is experimentally demonstrated, ensuring the controllability of polarity of the switching.