Field-free spin-orbit torque switching enabled by interlayer Dzyaloshinskii-Moriya interaction

• Published in: arXiv.org 2022-05
• Main Authors: He, Wenqing, Wan, Caihua, Zheng, Cuixiu, Wang, Yizhan, Wang, Xiao, Ma, Tianyi, Wang, Yuqiang, Guo, Chenyang, Luo, Xuming, Stebliy, Maksim E, Yu, Guoqiang, Liu, Yaowen, Ognev, Alexey V, Samardak, Alexander S, Han, Xiufeng
• Format: Article
• Language: English
• Subjects: Antiferromagnetism; Broken symmetry; Cobalt; Eigenvectors; Interlayers; Magnetic anisotropy; Magnetism; Multilayers; Platinum; Random access memory; Spintronics; Switching; Torque
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2205.06706

Perpendicularly magnetized structures that are switchable using a spin current under field-free conditions can potentially be applied in spin-orbit torque magnetic random-access memory(SOT-MRAM).Several structures have been developed;however,new structures with a simple stack structure and MRAM compatibility are urgently needed.Herein,a typical structure in a perpendicular spin-transfer torque MRAM,the Pt/Co multilayer and its synthetic antiferromagnetic counterpart with perpendicular magnetic anisotropy, was observed to possess an intrinsic interlayer chiral interaction between neighboring magnetic layers,namely the interlayer Dzyaloshinskii-Moriya interaction (DMI) effect. Furthermore, using a current parallel to the eigenvector of the interlayer DMI, we switched the perpendicular magnetization of both structures without a magnetic field, owing to the additional symmetry-breaking introduced by the interlayer DMI. This SOT switching scheme realized in the Pt/Co multilayer and its synthetic antiferromagnet structure may open a new avenue toward practical perpendicular SOT-MRAM and other SOT devices.