Electronic structure examination of the topological properties of CaMnSb2 by angle-resolved photoemission spectroscopy

We have carried out detailed high-resolution angle-resolved photoemission spectroscopy measurements and band structure calculations to study the electronic structure of $\mathrm{Ca}\mathrm{Mn}{\mathrm{Sb}}₂$. The observed Fermi surface mainly consists of one hole pocket around the $\mathrm{\ensuremath{\Gamma}}$ point and one tiny hole pocket at the $Y$ point. Strong spectral weight accumulation along the $\mathrm{\ensuremath{\Gamma}}\ensuremath{-}X$ direction is observed on the holelike Fermi surface around the $\mathrm{\ensuremath{\Gamma}}$ point, suggesting strong anisotropy of the density of states along the Fermi surface. The tiny hole pocket at the $Y$ point originates from an anisotropic Dirac-like band with the crossing point of the linear bands lying $\ensuremath{\sim}10$ meV above the Fermi level. These observations are in good agreement with the band structure calculations. In addition, we observe additional features along the $\mathrm{\ensuremath{\Gamma}}\ensuremath{-}Y$ line that cannot be accounted for by the band structure calculations. Our results provide important information in the understanding and exploration of novel properties in $\mathrm{Ca}\mathrm{Mn}{\mathrm{Sb}}₂$ and related materials.