Magnetic and Charge Order in the Three-Band Hubbard Model in the Underdoped Regime

The Copper-Oxide planes in cuprates have been at the center of the search for a theory of high temperature superconductivity. We conduct an extensive study of the ground state of the three-band Hubbard (Emery) model, in the underdoped regime. We focus on the magnetic and charge orders. Different parameter regimes are scanned to determine the magnetic and charge properties. We present mean field results from generalized Hartree-Fock calculations on large lattice sizes, aiming to capture the different kinds of orders that are stabilized in the thermodynamic limit. The importance of the oxygen p-orbitals as charge (hole) carriers clearly emerges from our data, resulting in a much more complex phase diagram with respect to the simpler single band Hubbard model.