Lifshitz transition in triangular lattice Kondo-Heisenberg model*

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 (J(H)) 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 byJ(H), 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 couplingJ(K), the Heisenberg antiferromagnetic interactionJ(H), and the ratio of the tunneling amplitude of f-electront(f)versus conduction electront(c). Our work provides a possible scenario to understand the Fermi surface topology and the quantum critical point in heavy-fermion compounds.