Thermoelectric transport in coupled double layers with interlayer excitons and exciton condensation
Jiuning Hu, David B. Newell, Yong P. Chen, Albert F. Rigosi
We employ quantum Boltzmann formalism to study the transport properties of generic double layer systems where the strong interlayer interaction allows the formation of interlayer excitons and exciton condensations. The Onsager relation for Coulomb drag resistivity is shown to be valid even when the exciton condensation is present. In addition we find the traditional thermoelectric figure of merit is no longer sufficient to predict the efficiency of thermoelectric power generation. We identify the importance of exciton formation, dissociation and condensation energies in allowing spontaneous thermoelectric power generation, and provide new principles for calculating the thermoelectric efficiency. Our theory offers new insights in designing thermoelectric modules of double layer systems with interlayer interactions that can enhance thermoelectric efficiency.