Bilayer effects on the electronic spectra of doped cuprates

作者：Pratap A^*; Lal R; Govind; Joshi SK

来源：Physical Review B, 2001, 64(22): 224512.

DOI：10.1103/PhysRevB.64.224512

A self-consistent perturbative approach has been used for investigating the effects of bilayer coupling in cuprate systems possessing two CuO2 layers per unit cell. The strong electron correlation effects which exist in the individual CuO2 layers are described by a t-t'-J model, and the coupling between the two intraunit cell layers is included via a layer-to-layer hopping matrix element t(perpendicular to) and an exchange interaction J(perpendicular to). Calculations of the electronic spectral function A(k,omega) have been made for different values of the hole concentration, temperature, and anisotropy for analyzing the appropriate. conditions for the splitting of the quasiparticle peak in the normal state. It has been found that the splitting of the quasiparticle peak becomes favorable for higher values of the hole doping and higher anisotropy ratios. Calculations of the imaginary part of the self-energy Sigma (")(l)(k,omega) have also been made. It has been found that Sigma (")(l)(k,omega) depends strongly on the momentum k and that the energy dependence of Sigma (")(l)(k,omega) changes qualitatively with the change of the momentum k. For k=(0,0) a Fermi liquid like behavior is found for low omega, while for other values of momentum, considered here, Sigma (")(l)(k,omega) varies like omega (alpha)(1 < < 2).

• 出版日期2001-12-1