Spin Dynamics in Fe3Sn2 frustrated kagome ferromagnet for room-temperature Skyrmion based technology

Magnetic skyrmions are attractive for ultra-dense data storage and distribution applications such as the racetrack memory (RM) [1]. Conventionally, the skyrmion’s topological protection is achieved by the Dzyaloshinskii-Moriya interaction (DMI). Recently, frustration in ferromagnetic (FM) crystals was predicted of also being capable of providing the topological protection of the skyrmion without relying on the DMI and the effect was immediately discovered in Fe3Sn2 bulk crystals [2,3]. Surprisingly, these skyrmions survive even at room temperature and are controllable by electrical current [4].  Interestingly, the kagome lattice of the Fe3Sn2 system is expected to possess a non-zero spin Berry curvature thereby giving rise to a large spin Hall effect (SHE) which is central to the skyrmion’s motion. In this work, we explore the underlying dynamics of the Fe3Sn2 system using a time-resolved optically probed Spin-Torque Ferromagnetic Resonance method. Our results indicate a significant SHE that is accompanied by a rich nonlinear response stemming from the unique crystals structure.

[1] S. S. P. Parkin, et al., "Magnetic Domain-Wall Racetrack Memory", Science 320, 190 (2008).

[2] Z. Hou, W. Ren, et al., "Observation of Various and Spontaneous Magnetic Skyrmionic Bubbles at Room Temperature in a Frustrated Kagome Magnet with Uniaxial Magnetic Anisotropy", Advanced Materials 29, 1701144 (2017).

[3] J. Tang, et al., "Target Bubbles in Fe3Sn2 Nanodisks at Zero Magnetic Field", ACS Nano 14, 10986 (2020).

[4] Z. Hou, et al., "Current-Induced Helicity Reversal of a Single Skyrmionic Bubble Chain in a Nanostructured Frustrated Magnet", Advanced Materials 32, 1904815 (2020).