Quantum oscillations and topological properties of a ${\mathrm{YB}}_2$ 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 ${\mathrm{YB}}_2$ that crystallizes in the hexagonal crystal structure with space group $P6/mmm$ and lattice constants $a=3.304\left(2\right)$ Å, $c=3.846\left(5\right)$ Å. The single crystal of ${\mathrm{YB}}_2$ 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 ${\mathrm{YB}}_2$ 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 ${\mathrm{YB}}_2$ exhibits bulk nodal lines with interesting drumhead topological surface states.