Bimeron Clusters in Chiral Antiferromagnets (2002.04387v4)

Abstract: A mgnetic bimeron is an in-plane topological counterpart of a magnetic skyrmion. Despite the topological equivalence, their statics and dynamics could be distinct, making them attractive from the perspectives of both physics and spintronic applications. In this work, we investigate an antiferromagnetic (AFM) thin film with interfacial Dzyaloshinskii-Moriya interaction (DMI), and introduce the AFM bimeron cluster as a new form of topological quasi-particle. Bimerons demonstrate high current-driven mobility as generic AFM solitons, while featuring anisotropic and relativistic dynamics excited by currents with in-plane and out-of-plane polarizations, respectively. Moreover, these spin textures can absorb other bimeron solitons or clusters along the translational direction to acquire a wide range of N\'eel topological numbers. The clustering involves the rearrangement of topological structures, and gives rise to remarkable changes in static and dynamical properties. The merits of AFM bimeron clusters reveal a potential path to unify multi-bit data creation, transmission, storage and even topology-based computation within the same material system, and may stimulate innovative spintronic devices enabling new paradigms of data manipulations.