Magnetic skyrmionic structures with variable topological charges in engineered Dzyaloshinskii-Moriya interaction systems
Heng Niu, Han Gyu Yoon, Hee Young Kwon, Zhiyuan Cheng, Siqi Fu, Hongying Zhu, B. F. Miao, Liang Sun, Yizheng Wu, Andreas K. Schmid, Kai Liu, C. Won, Haifeng Ding, Gong Chen
Abstract
Magnetic skyrmionic structures, including magnetic skyrmions and antiskyrmions, are characterized by swirling spin textures with non-trivial topologies. They are featured with specific topological charges, Q, which are of crucial importance in determining their topological properties. Owing to the invariance of the chiral nature, it is generally believed that Q is conserved in a given magnetic skyrmionic structure and is hard to alter. Here, we experimentally realize the control of Q of magnetic skyrmionic structures at room temperature in a Dzyaloshinskii-Moriya interaction (DMI) platform with spatially alternating signs. Depending on how many times it crosses the interfaces between DMI regions with opposite signs, the magnetic skyrmionic structures possess different Q. Modifying the DMI energy landscape through chemisorbed oxygen, a magnetic topological transition is realized. This creation and manipulation of magnetic skyrmionic structures with controllable Q, in particular the DMI-stabilized thin-film antiskyrmions and high-Q skyrmionic structures, enables a new degree of freedom to control their dynamics via a novel DMI confinement effect. Our findings open up an unexplored avenue on various topological magnetic skyrmionic structures and their potential applications. The authors experimentally realize the control of the topological charge of magnetic skyrmionic structures at room temperature in a Dzyaloshinskii-Moriya interaction (DMI) platform with spatially alternating signs. By modifying the DMI energy landscape through chemisorbed oxygen, a magnetic topological transition is realized.