Plethora of tunable Weyl fermions in kagome magnet Fe3Sn2 thin films

Abstract

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 the first 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 a unique platform that harbors an extraordinarily wide array of topological and correlated electron phenomena.

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Cited by in corpus (11)

• Orbital Magneto-Nonlinear Anomalous Hall Effect in Kagome Magnet Fe${}_3$Sn${}_2$
• Nanoscale visualization and spectral fingerprints of the charge order in ScV6Sn6 distinct from other kagome metals
• Spin-polarized imaging of the antiferromagnetic structure and field-tunable bound states in kagome magnet FeSn
• Kagome metals
• Persistent flat band splitting and strong selective band renormalization in a kagome magnet thin film
• Magnetic memory and distinct spin populations in ferromagnetic Co3Sn2S2
• Interorbital Antisymmetric Hopping Generated Flat Bands on Kagome and Pyrochlore Lattices
• Evolution of electronic and magnetic properties in Mn- and Co-alloyed ferromagnetic kagome metal Fe3Sn2
• Effect of Interlayer Stacking on the Electronic Properties of 1$T$-TaS${}_2$
• Electronic and optical properties of ternary kagome Rb2Ni3S4: a density functional study
• Effect of superconductivity by Nb and V substitution in kagome CaPd5