Weyl fermions with various chiralities in an f-electron ferromagnetic system: PrB4

Rare-earth tetraborides ($R$B$_{4}$) have attracted a lot of recent attention\ndue to their intriguing electronic, magnetic, and topological properties. We\nhave theoretically investigated topological properties of PrB$_{4}$, which is\nunique among $R$B$_{4}$ family due to its ferromagnetic ground state. We have\ndiscovered that PrB$_{4}$ is an intrinsic magnetic Weyl system possessing\nmultiple topological band crossings with various chiral charges.\nDensity-functional-theory band calculations combined with tight-binding band\nanalysis reveal large Fermi-arc surface states, which are characteristic\nfingerprints of Weyl fermions. Anomalous Hall conductivity is estimated to be\nvery large, ranging from 500 to 1000 ($\\Omega \\cdot$cm)$^{-1}$ near the Fermi\nlevel, which also demonstrates the topological Weyl character of ferromagnetic\nPrB$_{4}$. These findings suggest that PrB$_{4}$, being a potential candidate\nof magnetic Weyl system, would be a promising rare-earth topological system for\napplications to next-generation spintronic and photonic devices.\n