Lifshitz transitions in a heavy-Fermion liquid driven by short-range antiferromagnetic correlations in the two-dimensional Kondo lattice model
arXiv:1008.1698 · doi:10.1103/PhysRevB.83.033102
Abstract
The heavy-Fermion liquid with short-range antiferromagnetic correlations is carefully considered in the two-dimensional Kondo-Heisenberg lattice model. As the ratio of the local Heisenberg superexchange $J_{H}$ to the Kondo coupling $J_{K}$ increases, Lifshitz transitions are anticipated, where the topology of the Fermi surface (FS) of the heavy quasiparticles changes from a hole-like circle to four kidney-like pockets centered around $(Ï,Ï)$. In-between these two limiting cases, a first-order quantum phase transition is identified at $J_{H}/J_{K}=0.1055$ where a small circle begins to emerge within the large deformed circle. When $J_{H}/J_{K}=0.1425$, the two deformed circles intersect each other and then decompose into four kidney-like Fermi pockets via a second-order quantum phase transition. As $J_{H}/J_{K}$ increases further, the Fermi pockets are shifted along the direction ($Ï,Ï$) to ($Ï/2,Ï/2$), and the resulting FS is consistent with the FS obtained recently using the quantum Monte Carlo cluster approach to the Kondo lattice system in the presence of the antiferrmagnetic order.
4 pages, 5 figures