Planar and local anisotropies in the Kondo necklace model

Using the density matrix renormalization group method, we study the one‐dimensional Kondo necklace model including two anisotropies: η in the XY interaction of the conduction chain, and Δ in the local Kondo coupling between localized and conduction spins. For different values of the anisotropies, we calculate the energy gap and estimate the quantum critical points in which a phase transition from antiferromagnetic to spin liquid states takes place, assuming a Kosterlitz–Thouless‐like behavior. For the case $\eta = 0$ , the system remains in a spin liquid state for the different Δ considered, but when $\eta \ne 0$ , Δ markedly affects the location of the critical points. We also calculate correlation functions for a specific case, in order to support our gap results.