  The electronic states in incommensurate (IC) helical magnets are studied
theoretically from the viewpoint of the localization/delocalization. It is
found that in the multi-band system with relativistic spin-orbit interaction,
the electronic wavefunctions show both the extended and localized natures along
the helical axis depending on the orbital, helical wavenumber, and the
direction of the plane on which spins rotate. Possible realization of this
localization is discussed.
