Normal state Fermi surface of cuprates: effects of bilayer interactions

In this paper, we use Green's function formalism to calculate the electronic spectral function for cuprates having two CuO2 layers in the same unit cell. From the knowledge of spectral function at various k-points in the Brillioun zone, we construct and analyze the effects of coupling between the two layers (i.e. the intrabilayer interactions) on the Fermi surface of these systems. For low concentration of hole density, we find a hole-like Fermi surface centered at (pi, pi) point of Brillioun zone. For weak intrabilayer interactions, we observe that the Fermi surface may change from hole-like to electron-like on increasing the hole concentration. On the other hand, the Fermi surface remains hole-like for the whole range of hole density when intrabilayer interactions are strong enough. In addition, the electronic spectral function obtained with higher resolution in momentum space suggests the presence of a shadow Fermi surface in these systems. We have also identified the existence of splitting of electronic states due to the intrabilayer interactions at higher hole concentration in the bilayer systems. (C) 2003 Elsevier Science B.V. All rights reserved.