Physical review. B, Condensed matter
Specific heat of the half-filled Hubbard chain: A Feynman path-integral Monte Carlo investigation
Joachim Schulte, Michael C. Böhm
Abstract
The specific heat C of the one-dimensional half-filled Hubbard model is studied by Feynman path-integral quantum Monte Carlo simulations as a function of temperature (T). The strength of the electronic correlations is modified by a variable intramolecular two-electron repulsion U. For weak correlations, C shows a single maximum. For intermediate correlations C has two maxima in the T interval studied. For strong correlations only one maximum and one minimum in C are found in the T interval considered. The influence of spin and electronic excitations on the T dependence of C are discussed. The C data are correlated with calculated probabilities of single occupancy, electronic charge fluctuations, and the electronic chemical potential. \textcopyright{} 1996 The American Physical Society.