Quadratic nodal point with large surface arc states in half-Heusler material ScBiPt

Recently, the research focus of topological states in electronic systems has been shifted from the conventional linear type to high order dispersion, in which more exotic physical properties are exhibited, such as high topological charge, large magnetoresponse and unusual transport behavior. In this work, based on first principles calculations, we proposed a quadratic nodal point semimetal, the half-Heusler material ScBiPt. Detailed band structures reveal that an ideal nodal point is present exactly at the Fermi level and, more importantly, it exhibits quadratic dispersion along all directions, which has also been confirmed from the symmetry analyzation and effective model argument. Moreover, when the spin orbital coupling effect is considered, the nodal point changes from triple to quadruple degeneracy but the quadratic dispersion is still maintained. Two prominent arc surface states are emanated from the nodal point and they are well separated from the bulk bands, making the future experimental verification extremely beneficial. Overall, the current quadratic nodal point material with multiple advantages can serve as an ideal platform and the relative studies can be immediately inspired and advanced. © 2022