Charge dynamics in doped triangular antiferromagnets

Within the framework of the fermion-spin theory based on the charge-spin se paration, the charge dynamics of the doped antiferromagnet on a triangular lattice is studied. The holon part is treated by using the loop expansion t o the second order. It is shown that the charge dynamics is mainly caused b y charged holons moving in the background of spinon excitations. The optica l conductivity spectrum shows an unusual behavior at low energies and an an omalous midinfrared band, while the resistivity exhibits a nonlinearity in temperatures.