Interfacing Determinant Quantum Monte Carlo and Density Functional Theory

Over the last decade many body theory and electronic structure calculations have come together within the ``LDA+DMFT" approach in which dynamical mean field theory (DMFT) provides a frequency dependent self-energy $\Sigma(\omega)$ for electronic structure calculation within the local density approximation (LDA). Here we describe initial results with a new approach which uses the determinant Quantum Monte Carlo method to supply the self energy. This technique has the advantage of providing a momentum dependent $\Sigma({\bf k},\omega)$. However, the fermion sign problem can limit the ability to access the ground state value of the self energy. We present tests of the approach on a model of cuprate superconductors.