Thermal Transport of a Delta-Doped Multilayer with Strongly Correlated Electrons

Abstract

We present a theory for the charge and heat transport in a multilayer made of three sets of planes with strongly correlated electrons. The Mott insulator planes make the left and right barrier; a few delta-doped planes which are close to the metal-insulator transition make a conduction channel. In such a device, the currents can only flow parallel to the interfaces. The electron dynamics is described by the Falicov-Kimball model which can be solved for arbitrary large on-site correlation with an inhomogeneous DMFT algorithm. The charge reconstruction induced by the interfaces is taken into account by solving the Poisson equation. We derive the current density operators of the model and compute the thermoelectric coefficients by linear response theory. By tuning the number of electrons in the conducting channel we bring the chemical potential in the region where the renormalized transport density of states is very steep. This enhances the thermoelectric performance of the device. The results are illustrated by showing the reconstructed charge profile, transport density of states, the electrical resistance, the Seebeck coefficient, the Lorenz number, and the figure-of-merit.