Highly efficient field-free switching of perpendicular yttrium iron garnet with collinear spin current
Man Yang, Liang Sun, Yulun Zeng, Jun Cheng, Kang He, Xi Yang, Ziqiang Wang, Longqian Yu, Heng Niu, Tongzhou Ji, Gong Chen, B. F. Miao, X. R. Wang, Haifeng Ding
Abstract
Yttrium iron garnet, a material possessing ultralow magnetic damping and extraordinarily long magnon diffusion length, is the most widely studied magnetic insulator in spintronics and magnonics. Field-free electrical control of perpendicular yttrium iron garnet magnetization with considerable efficiency is highly desired for excellent device performance. Here, we demonstrate such an accomplishment with a collinear spin current, whose spin polarization and propagation direction are both perpendicular to the interface. Remarkably, the field-free magnetization switching is achieved not only with a heavy-metal-free material, Permalloy, but also with a higher efficiency as compared with a typical heavy metal, Pt. Combined with the direct and inverse effect measurements, we ascribe the collinear spin current to the anomalous spin Hall effect in Permalloy. Our findings provide a new insight into spin current generation in Permalloy and open an avenue in spintronic devices.