Spectral behavior of the electronic states of bilayer cuprate systems using a slave fermion approach

Abstract

The spectral function for electrons in the normal state of a bilayer cuprate is calculated by employing a slave fermion approach. The electron correlations in the CuO2 layers in these cuprates are described by a t-J model, and the electronic coupling between the two CuO2 layers within the same unit cell is introduced via a hopping matrix element (t⊥) and an exchange interaction (J⊥). The spectral function is calculated for different values of the hole concentration, temperature, and anisotropy at various values of the momentum (kx,ky). It is found that the bilayer coupling (t⊥) significantly affects the behavior of the spectral function. The spectral function around the momentum value (π, 0) for a coupled bilayer cuprate shows a peak much sharper than that for a system of uncoupled layers. Our calculation also suggests a splitting of electronic states of the bilayer cuprates along the (π, 0) direction for the heavily overdoped regime. Calculations of the imaginary part of the self-energy Σ1″(k,ω) for a bilayer system have also been presented. It is found that Σ1″(k,ω) depends strongly on the momentum and shows a ωα dependence on energy with 1.2<α<1.5 for values of the parameters t and J considered in the present calculations.

Source-reported materials — not catalogue approval

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