Interaction corrections to the thermopower: the role of the density of states

At low temperatures, due to the interplay of disorder and interactions, thermal and electrical conductivity acquire quantum corrections to the classical Drude-Boltzmann results. Although interaction corrections to electrical and thermal conductivity have been studied extensively, there has been relatively little research on corrections to the thermopower. Thermopower is sensitive to particle-hole asymmetry, and thus offers insight into how particles and holes behave differently in a system. Therefore, the energy-dependence of quantities such as the diffusion coefficient and the density of states becomes important for the calculation of the thermopower. Previously, we have investigated the interaction corrections to the thermopower assuming a constant density of states ^[1]. Here, we study the consequence of the energy-dependence of the density of states and the diffusion coefficient on the corrections to the thermopower using the diagrammatic Green’s function technique.

[1] Z. I. Jitu, G. Schwiete, Interaction corrections to the thermopower of the disordered two-dimensional electron gas, Phys. Rev. B 110, L041404 (2024).