Effects of lattice geometry on thermopower properties of the repulsive Hubbard model

Abstract

We obtain the Seebeck coefficient or thermopower $S$, which determines the conversion efficiency from thermal to electrical energy, for the two-dimensional Hubbard model on different geometries (square, triangular, and honeycomb lattices) for different electronic densities and interaction strengths. Using Determinantal Quantum Monte Carlo (DQMC) we find the following key results: (a) the bi-partiteness of the lattice affects the doping dependence of $S$; (b) strong electronic correlations can greatly enhance $S$ and produce non-trivial sign changes as a function of doping especially in the vicinity of the Mott insulating phase; (c) $S(T)$ near half filling can show non-monotonic behavior as a function of temperature. We emphasize the role of strong interaction effects in engineering better devices for energy storage and applications, as captured by our calculations of the power factor $PF=S^2\sigma$ where $\sigma$ is the dc conductivity.

10 pages, 8 figures

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Cited by in corpus (4)

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• Electronic interactions in a vacancy-engineered honeycomb lattice: Transition from a nodal-line semimetal to a magnetic insulator
• Specific heat and density anomaly in the Hubbard model
• Thermoelectric effect on diffusion in the two-dimensional Hubbard model