Electronic structure of the antiferromagnetic ground state of La₂CuO₄beyond LDA + U method

With regard the Hubbard Hamiltonian, we use a Bogolyubov transformation and within a spin density wave mean field, where the antiferromagnetic correlations of wave vector Q = (π/a,π/a) are included. This gives a new energy spectrum that is calculated starting from the band structure of La2CuO4 determined in the local density formalism. We calculate the self-energy in this new ground state using the random phase approximation and a double Lorentzian as a non-interacting density of states. With this self-energy, Dyson's equation is solved by diagonalizing the Green's function in /c-space. The density of states is obtained by considering the renormalization factor and the lifetimes of the quasiparticle states in each pole. This leads to the splitting of the input density of states that is calculated in the local density formalism. © 2000 Elsevier Science B.V. All rights reserved.