Coexistence of topological nontrivial phase and Rashba-type surface state in HoSb*

Using the high resolution angle-resolved photoemission spectroscopy (ARPES), magnetotransport, and parallel first-principles modeling, we report the discovery of a topologically nontrivial state coexisting with a Rashba-type surface state in a rare earth monopnictide semimetal. Our theoretical analysis reveals the presence of bulk band inversions at the Γ and X points of the Brillouin zone (BZ). Interestingly, the upper part of the observed Rashba-type surface state coincides with the nontrivial surface state at the X point. Magnetotransport study indicates that HoSb can be characterized as a correlated nearly-complete electron-hole-compensated semimetal. Therefore, our findings provide HoSb as a new materials platform for exploring the interplay between coexisting topological and Rashba-type surface state and the non-saturating XMR effect in the rare earth monopnictide family.