First principles electronic model for high-temperature superconductivity

Abstract

Using the structural data of the ${\mathrm{La}}_2{\mathrm{CuO}}_4$ compound both in the distorted low-temperature tetragonal phase and in the isotropic phase, we have derived an effective $t-J$ model with hoppings t and superexchange interactions J extended up to the fourth- and second-nearest-neighbors, respectively. By numerically studying this Hamiltonian we have then reproduced the main experimental features of this high-temperature superconductivity compound: d-wave superconductivity is stabilized at small but finite doping $\delta \gtrsim 6\%$ away from the antiferromagnetic region and some evidence of dynamical stripes is found at commensurate filling 1/8.