  Magnetization processes of frustrated Kondo necklace model are studied by
means of a density matrix renormalization group (DMRG) method and an elementary
band theory based on a bond-operator formalism. The DMRG calculations clearly
show the cusp singularity in a low-magnetization region ($0<m<1/2$) besides
that in a high-magnetization region ($1/2<m<1$) which is expected from previous
studies on the magnetization curve of the Majumdar-Ghosh model. An appearance
mechanism of the low-magnetization cusp is interpreted in terms of a
double-well shape of a low-energy band arising from frustrations between
nearest- and next-nearest-neighbor interactions. We also discuss critical
behaviors of magnetization near the cusp and obtain a phase diagram showing
whether the cusp appears in the magnetization curve or not.
