Controlling and imaging chiral spin textures

Chirality in magnetic materials is fundamentally interesting and holds potential for logic and memory applications [1,2,3]. Using spin-polarized low-energy electron microscopy at National Center for Electron Microscopy, we recently observed chiral domain walls in thin films [4,5]. We developed ways to tailor the Dzyaloshinskii-Moriya interaction, which drives the chirality, by interface engineering [6] and by forming ternary superlattices [7]. We find that spin-textures can be switched between left-handed, right-handed, cycloidal, helical and mixed domain wall structures by controlling uniaxial strain in magnetic films [8]. We also demonstrate an experimental approach to stabilize skyrmions in magnetic multilayers without external magnetic field [9]. These results exemplify the rich physics of chirality associated with interfaces of magnetic materials. [1] A. Fert et al. \textit{Nat. Nanotechnol.} \textbf{8}, 152 (2013). [2] N. Nagaosa et al. \textit{Nat. Nanotechnol.} \textbf{8}, 899 (2013). [3] W. Jiang et al. \textit{Science} \textbf{349}, 283 (2015). [4] G. Chen, et al. \textit{Phys. Rev. Lett}. \textbf{110}, 177204 (2013). [5] G. Chen, et al. \textit{Adv. Mater}. \textbf{27}, 5738 (2015). [6] G. Chen, et al. \textit{Nat. Commun.} \textbf{4}, 2671 (2013). [7] G. Chen, et al. \textit{Appl. Phys. Lett.} \textbf{106}, 062404 (2015). [8] G. Chen, et al. \textit{Nat. Commun.} \textbf{6}, 6598 (2015). [9] G. Chen, et al. \textit{Appl. Phys. Lett.} \textbf{106}, 242404 (2015).