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Thermodynamics of the planar Hubbard model

J. Bonca·P. Prelovsek
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Abstract

The thermodynamic properties: specific heat, entropy, spin susceptibility $χ_s$ and charge susceptibility $χ_c$ are studied as a function of temperature and doping within the two-dimensional Hubbard model with various $U/t=4 - 12$. Quantities are calculated using the finite-temperature Lanczos method with additional phase-averaging for a system of $4\times 4$ sites. Results show that the entropy at low $T$ reaches a maximum near half-filling at the electron density $n \sim 1\pm 0.15$ in the whole regime of studied $U/t$. The pseudogap in $χ_s(T)$ becomes clearly pronounced for $U/t \geq 8$ while $χ_c$ shows a maximum close to half-filling. The relation of results to those within the t-J model and to experiments is discussed.

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J. Bonca, P. Prelovsek. 2002-06-04. Thermodynamics of the planar Hubbard model. https://doi.org/10.1103/physrevb.67.085103

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