Filters

2022 - 20232

More filters

20232
Reset filters

Settings

Publisher: [London] : Nature Publishing Group × Subject: Surfaces, interfaces and thin films ×

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Plethora of tunable Weyl fermions in kagome magnet Fe3Sn2 thin films
    ([London] : Nature Publishing Group, 2022) Ren, Zheng; Li, Hong; Sharma, Shrinkhala; Bhattarai, Dipak; Zhao, He; Rachmilowitz, Bryan; Bahrami, Faranak; Tafti, Fazel; Fang, Shiang; Ghimire, Madhav Prasad; Wang, Ziqiang; Zeljkovic, Ilija
    Interplay of magnetism and electronic band topology in unconventional magnets enables the creation and fine control of novel electronic phenomena. In this work, we use scanning tunneling microscopy and spectroscopy to study thin films of a prototypical kagome magnet Fe3Sn2. Our experiments reveal an unusually large number of densely-spaced spectroscopic features straddling the Fermi level. These are consistent with signatures of low-energy Weyl fermions and associated topological Fermi arc surface states predicted by theory. By measuring their response as a function of magnetic field, we discover a pronounced evolution in energy tied to the magnetization direction. Electron scattering and interference imaging further demonstrates the tunable nature of a subset of related electronic states. Our experiments provide a direct visualization of how in-situ spin reorientation drives changes in the electronic density of states of the Weyl fermion band structure. Combined with previous reports of massive Dirac fermions, flat bands, and electronic nematicity, our work establishes Fe3Sn2 as an interesting platform that harbors an extraordinarily wide array of topological and correlated electron phenomena.
  • Thumbnail Image
    Item
    Intertwined electronic and magnetic structure of the van-der-Waals antiferromagnet Fe2P2S6
    ([London] : Nature Publishing Group, 2023) Koitzsch, A.; Klaproth, T.; Selter, S.; Shemerliuk, Y.; Aswartham, S.; Janson, O.; Büchner, B.; Knupfer, M.
    Many unusual and promising properties have been reported recently for the transition metal trichalcogenides of the type MPS3 (M = V, Mn, Fe, Ni..), such as maintaining magnetic order to the atomically thin limit, ultra-sharp many-body excitons, metal-insulator transitions and, especially for Fe2P2S6, giant linear dichroism among others. Here we conduct a detailed investigation of the electronic structure of Fe2P2S6 using angle-resolved photoemission spectroscopy, q-dependent electron energy loss spectroscopy, optical spectroscopies and density functional theory. Fe2P2S6 is a Mott insulator with a gap of E gap ≈ 1.4 eV and zigzag antiferromagnetism below T N = 119 K. The low energy excitations are dominated by Fe 3d states. Large and sign-changing linear dichroism is observed. We provide a microscopic mechanism explaining key properties of the linear dichroism based on the correlated character of the electronic structure, thereby elucidating the nature of the spin-charge coupling in Fe2P2S6 and related materials.