Exact results for a Hubbard chain with long-range hopping

Abstract
We give the exact spectrum and thermodynamics for a long-range hopping Hubbard chain with linear dispersion. This model exhibits a Mott-Hubbard metal-insulator transition at half filling when the interaction strength U equals the bandwidth W. The solution for UW also covers the corresponding t-J model, which reduces to the spin model of Haldane and Shastry at half filling. We mention possible extensions of the model in one and higher dimensions.