Order-Ncalculations for thermoelectric power factor based on linear response theory

We present an order-Nquantum transport calculation methodology to evaluate thermoelectric transport coefficients, such as electric conductivity and Seebeck coefficient. Different from a conventional method using the electric conductivity spectrum, it obtains the coefficients directly from the correlation function between heat and electric current based on linear response theory. As an example, we apply the methodology to a two-dimensional square-lattice model with static disorder and confirm that the calculated results are consistent with those obtained by the conventional method. The proposed methodology provides an effective approach to evaluate the thermoelectric performance of micron-scale materials based on quantum mechanics from an atomistic viewpoint.