Vivaldo L. Campo, Jr., just left after a brief visit. Vivaldo is one of my longest-time collaborators, but I had not seen him in the flesh in many years. It was great to discuss Physics with him extensively. He gave a very interesting seminar on the extension of lattice DFT to finite temperatures – see abstract below.
Density-functional theory approach to the thermodynamics of the harmonically confined one-dimensional Hubbard model
Vivaldo L. Campo, Federal University of Sao Carlos (UFSCar), Brazil
At 2pm in Room 110, Ingram Building
The thermodynamics of the inhomogeneous one-dimensional repulsive fermionic Hubbard model with parabolic confinement is studied by a density-functional theory approach, based on Mermin’s generalization to finite temperatures. A local-density approximation (LDA), based on exact results for the homogeneous model, is used to approximate the correlation part in the Helmholtz free-energy, comprising the thermodynamic Bethe ansatz LDA (TBALDA). The general presentation of the method is given and then a classical thermodynamic treatment of the confined system is developed with the focus on global properties of large systems. It is observed that, depending on the temperature and specific volume, the system has its temperature increased under adiabatic expansion. The efect grows with the intra-site interaction U and can be understood considering the peculiar behavior of the correlation entropy for the Hubbard model around half-filling.