Thermoelectric Transports in Charge-Density Systems

Collective-mode contribution to the thermoelectric properties in charge-density-wave systems is studied. Thermoelectric power and thermal conductivity is derived from Fröhlich Hamiltonian with linear response theory. In this study, we ignore quasi-particle contribution and impurity effects. Energy dissipation is attributed to nonlinear interaction between phase and amplitude modes. We find that temperature dependence of correlation function between electric and heat currents is the same as that of electric conductivity, and thermoelectric power is inversely proportional to temperatures. We also find that thermal conductivity has nearly constant value at the temperatures above amplitude mode gap, and has exponentially low value at the temperatures sufficiently below it.