Density-functional study of the Mott gap in the Hubbard model
Density-functional study of the Mott gap in the Hubbard model
We study the Mott insulating phase of the one-dimensional Hubbard model using a local-density approximation (LDA) that is based on the Bethe Ansatz (BA). Unlike conventional functionals, the BA-LDA has an explicit derivative discontinuity. We demonstrate that, as a consequence of this discontinuity, the BA-LDA yields the correct Mott gap, …