Lifshitz transition in triangular lattice Kondo-Heisenberg model**Project supported by the National Natural Science Foundation of China (Grant Nos. 11674139, 11704166, and 11834005), the Fundamental Research Funds for the Central Universities, China, and PCSIRT, China (Grant No. IRT-16R35).

Abstract

Motivated by recent experimental progress on triangular lattice heavy-fermion compounds, we investigate possible Lifshitz transitions and the scanning tunnel microscope (STM) spectra of the Kondo–Heisenberg model on the triangular lattice. In the heavy Fermi liquid state, the introduced Heisenberg antiferromagnetic interaction (JH) results in the twice Lifshitz transition at the case of the nearest-neighbour electron hopping but with next-nearest-neighbour hole hopping and the case of the nearest-neighbour hole hopping but with next-nearest-neighbour electron hopping, respectively. Driven by JH, the Lifshitz transitions on triangular lattice are all continuous in contrast to the case on square lattice. Furthermore, the STM spectra shows rich line-shape which is influenced by the Kondo coupling JK, the Heisenberg antiferromagnetic interaction JH, and the ratio of the tunneling amplitude of f-electron tf versus conduction electron tc. Our work provides a possible scenario to understand the Fermi surface topology and the quantum critical point in heavy-fermion compounds.