Variational Monte Carlo Study of the Kondo Necklace Model with   Geometrical Frustration
  We investigate the ground state of the Kondo necklace model on geometrically-frustrated lattices by the variational Monte Carlo simulation. To explore the possibility of a partially-ordered phase, we employ an extension of the Yosida-type wave function as a variational state, which can describe a coexistence of spin-singlet formation due to the Kondo coupling and magnetic ordering by the Ruderman-Kittel-Kasuya-Yosida interaction. We show the benchmark of the numerical simulation to demonstrate the high precision brought by the optimization of a large number of variational parameters. We discuss the ground-state phase diagram for the model on the kagome lattice in comparison with that for the triangular-lattice case. 
Yukitoshi Motome, Kyoya Nakamikawa, Youhei Yamaji, and Masafumi   Udagawa
cond-mat.str-el