Damping of charge-density-wave motion

Starting from a three-dimensional generalization of the Lee-Rice-Anderson Hamiltonian (wherein the electron motion is still treated one dimensionally), the damping of a field-driven q=0 phason is studied. The dominant contribution to the phason damping comes from its scattering by a thermal phason to produce two q{≠}0 phasons. Taking into account the nonlinearity of the phason spectrum, we find that the associated charge-density-wave (CDW) conductivity [in the (10--100)-GHz region] is comparable to that in the metallic phase, in rough agreement with experiment. The contribution to damping of phason scattering by thermal amplitude modes is a factor of {~}(1/5) smaller than that of thermal phasons. Comparison of the order of magnitude of the damping coefficient with experiment is discussed, and possible theoretical improvements are proposed.