Rare-earth tetraborides ($R$B$_{ 4}$) have attracted a lot of recent attention due to their intriguing electronic, magnetic, and topological properties. We have theoretically investigated topological properties of PrB$_{ 4}$, which is unique among $R$B$_{ 4}$ family due to its ferromagnetic ground state. We have discovered that PrB$_{ 4}$ is an intrinsic magnetic Weyl system possessing multiple topological band crossings with various chiral charges. Density-functional-theory band calculations combined with tight-binding band analysis reveal large Fermi-arc surface states, which are characteristic fingerprints of Weyl fermions. Anomalous Hall conductivity is estimated to be very large, ranging from 500 to 1000 ($\Omega \cdot$cm)$^{ -1}$ near the Fermi level, which also demonstrates the topological Weyl character of ferromagnetic PrB$_{ 4}$. These findings suggest that PrB$_{ 4}$, being a potential candidate of magnetic Weyl system, would be a promising rare-earth topological system for applications to next-generation spintronic and photonic devices.
Categories: cond-mat.str-el