  Monoaxial chiral magnets can form a noncollinear twisted spin structure
called the chiral helimagnetic state. We study magnetic properties of such a
chiral helimagnetic state, with emphasis on the effect of itinerant electrons.
Modeling a monoaxial chiral helimagnet by a one-dimensional Kondo lattice model
with the Dzyaloshinskii--Moriya interaction, we perform a variational
calculation to elucidate the stable spin configuration in the ground state. We
obtain a chiral helimagnetic state as a candidate for the ground state, whose
helical pitch is modulated by the model parameters: the Kondo coupling, the
Dzyaloshinski--Moriya interaction, and electron filling.
