Competing states in the two-dimensional frustrated Kondo-necklace model

The interplay between Kondo screening, indirect magnetic interaction and geometrical frustration is studied in the two-dimensional Kondo-necklace model on triangular lattice. Using infinite projected entangled pair states (iPEPS), we compute ground state as a function of antiferromagnetic local $J_K$ Ising-type direct spin-spin $I_z$ . As opposed to previous studies, do not find partial screening (PKS) isotropic limit $I_z = 0$ but same behavior unfrustrated case, i.e. phase transition paradigmatic phases Doniach competition: (i) disordered consisting spin-singlets at strong (ii) magnetically ordered weak For > 0$, PKS again opposite that competition with second candidate found before. This characterized by strongly polarized central spin each hexagon its anti-parallel, weakly (i.e. partially screened) neighbors. We name it (CS) phase.