Dual Fermions Study of the 2D Hubbard Model

The Hubbard model is believed to contain strongly correlated physics relevant to high temperature superconductors. As in the hole-doped cuprates, the Hubbard model's phase diagram includes a superconducting dome below a pseudogap phase that is characterized by a momentum selective suppression of low energy excitations. Numerical studies of this phase thus require high resolution in both momentum and energy in order to resolve the details of the Fermi surface, which is challenging with numerical methods like dynamical mean field theory and its cluster extensions. In this work we apply the recently developed dual fermions technique to study the spectral function at high resolution in $k$ and $\omega$. We extract properties of the electronic structure in the high temperature regime of the 2D Hubbard model, analytically continued to real frequencies, and study the on-set and evolution of the momentum selective behavior for variation in model parameters.