Three-dimensional electronic structure in ferromagnetic Fe3Sn2 with breathing kagome bilayers

A large anomalous Hall effect (AHE) has been observed in ferromagnetic ${\mathrm{Fe}}_{3}{\mathrm{Sn}}_{2}$ with breathing kagome bilayers. To understand the underlying mechanism for this, we investigate the electronic structure of ${\mathrm{Fe}}_{3}{\mathrm{Sn}}_{2}$ by angle-resolved photoemission spectroscopy (ARPES). In particular, we use both vacuum ultraviolet light (VUV) and soft x ray (SX), which allow surface-sensitive and relatively bulk-sensitive measurements, respectively, and distinguish bulk states from surface states, which should be unlikely related to the AHE. While VUV-ARPES observes two-dimensional bands mostly due to surface states, SX-ARPES reveals three-dimensional band dispersions with a periodicity of the rhombohedral unit cell in the bulk. Our data show a good consistency with a theoretical calculation based on density functional theory, suggesting a possibility that ${\mathrm{Fe}}_{3}{\mathrm{Sn}}_{2}$ is a magnetic Weyl semimetal.