Creating zero-field skyrmions in exchange-biased multilayers through X-ray illumination
Guang Yao, Iuliia Bykova, Yizhou Liu, Guoqiang Yu, E. Goering, Markus Weigand, Joachim Gräfe, Se Kwon Kim, Junwei Zhang, Hong Zhang, Z. R. Yan, Caihua Wan, Jiafeng Feng, Xiao Wang, Chenyang Guo, Hongxiang Wei, Yong Peng, Yaroslav Tserkovnyak, Xiufeng Han, Gisela Schütz
Abstract
Skyrmions, magnetic textures with topological stability, hold promises for high-density and energy-efficient information storage devices owing to their small size and low driving-current density. Precise creation of a single nanoscale skyrmion is a prerequisite to further understand the skyrmion physics and tailor skyrmion-based applications. Here, we demonstrate the creation of individual skyrmions at zero-field in an exchange-biased magnetic multilayer with exposure to soft X-rays. In particular, a single skyrmion with 100-nm size can be created at the desired position using a focused X-ray spot of sub-50-nm size. This single skyrmion creation is driven by the X-ray-induced modification of the antiferromagnetic order and the corresponding exchange bias. Furthermore, artificial skyrmion lattices with various arrangements can be patterned using X-ray. These results demonstrate the potential of accurate optical control of single skyrmion at sub-100 nm scale. We envision that X-ray could serve as a versatile tool for local manipulation of magnetic orders.