From Trivial Kondo Insulator Ce₃Pt₃Bi₄ to Topological Nodal-line Semimetal Ce₃Pd₃Bi₄

Using the density functional theory combined with dynamical mean-field theory, we have performed systematic study of the electronic structure and its band topology properties of Ce₃Pt₃Bi₄ and Ce₃Pd₃Bi₄. At high temperatures (∼290 K), the electronic structures of both compounds resemble the open-core 4f density functional calculation results. For Ce₃Pt₃Bi₄, clear hybridization gap can be observed below 72 K, and its coherent momentum-resolved spectral function below 18 K exhibits an topologically trivial indirect gap of ∼6 meV and resembles density functional band structure with itinerant 4f state. For Ce₃Pd₃Bi₄, no clear hybridization gap can be observed down to 4 K, and its momentum-resolved spectral function resembles electron-doped open-core 4f density functional calculations. The band nodal points of Ce₃Pd₃Bi₄ at 4 K are protected by the gliding-mirror symmetry and form ringlike structure. Therefore, the Ce₃Pt₃Bi₄ compound is topologically trivial Kondo insulator while the Ce₃Pd₃Bi₄ compound is a topological nodal-line semimetal.