Quantum oscillations and topological properties of a YB2 single crystal

The search for ideal quantum materials with symmetry-protected topological states continues to intrigue intense research activities in condensed matter physics. Here, we present single crystal growth, Fermi surface studies, and topological state analysis of a binary boride YB₂ that crystallizes in the hexagonal crystal structure with space group $P6/mmm$ and lattice constants $a=3.304(2)$ {}, $c=3.846(5)$ {}. The single crystal of YB₂ was grown by the Czochralski method, in a tetra-arc furnace. The anisotropic physical properties are reported by performing the electrical transport and magnetization measurements. The electrical resistivity confirms the metallic nature of YB₂ while the magnetization reveals that it is a diamagnetic material. Interestingly in the magnetoresistance and magnetization measurements, we observe quantum oscillations, namely, Shubnikov-de Haas (SdH) oscillations and de Haas van Alphen (dHvA) oscillations for the magnetic field direction parallel to [0001]. The quantum oscillations likely originates from a hole pocket centered at the A point. Our first-principles results unveil that YB₂ exhibits bulk nodal lines with interesting drumhead topological surface states.