Thermodynamics of the one-dimensional half-filled Hubbard model in the spin-disordered regime

Abstract

We analyze the Thermodynamic Bethe Ansatz equations of the one-dimensional half-filled Hubbard model in the "spin-disordered regime", which is characterized by the temperature being much larger than the magnetic energy scale but small compared to the Mott-Hubbard gap. In this regime the thermodynamics of the Hubbard model can be thought of in terms of gapped charged excitations with an effective dispersion and spin degrees of freedom that only contribute entropically. In particular, the internal energy and the effective dispersion become essentially independent of temperature. An interpretation of this regime in terms of a putative interacting-electron system at zero temperature leads to a metal-insulator transition at a finite interaction strength above which the gap opens linearly. We relate these observations to studies of the Mott-Hubbard transition in the limit of infinite dimensions.

15 pages, 3 figures

References in corpus (5)

• Green's function for magnetically incoherent interacting electrons in one dimension
• Electron spectra close to a metal-to-insulator transition
• Systematic Mapping of the Hubbard Model to the Generalized t-J Model
• High temperature expansion of emptiness formation probability for isotropic Heisenberg chain
• The Mott insulator - 10th order perturbation theory extended to infinite order using QMC