Finite temperature non-Fermi liquids

Finite temperature properties of a non-Fermi liquid system is analysed base d on the temperature dependent Bethe Ansatz equations. We focus mostly on t he one-dimensional Hubbard model, as this model is the prototypical model f or a non-Fermi liquid system and this is an, ideal system to study since it is exactly solvable even at finite temperatures. At finite temperatures sp in, and charge separation still holds, however the low energy excitations h ave a spin gap. The properties of this state will be discussed.