Evidence of nontrivial Berry phase and Kondo physics in SmBi

Realization of semimetals with nontrivial topologies such as Dirac and Weyl semimetals has provided a boost to the study of these quantum materials. The presence of electron correlation makes the system even more exotic due to enhanced scattering of charge carriers, Kondo screening, etc. Here, we studied the electronic properties of high-quality single-crystalline SmBi employing magnetic and resistivity measurements. The temperature dependence of the magnetization reveals two magnetic transitions: an antiferromagnetic order with a N\'eel temperature of ~9 K and a second transition at a lower temperature (= 7 K). The electrical resistivity shows an upturn typical of a Kondo system, and the estimated Kondo temperature is found to be close to the N\'eel temperature. The magnetization as a function of the applied magnetic field exhibits pronounced quantum oscillations at low temperatures. Using a Landau level fan diagram analysis, a nontrivial Berry phase is identified for a Fermi pocket suggesting topological properties of this material. These results provide an example of the fermiology in the antiferromagnetic state of a Kondo system and open up a new paradigm to explore the Dirac fermion physics in correlated topological materials via interplay of Kondo interaction, magnetism, and topological order.