Pseudogap formation in an electronic system with d-wave attraction at low density

On the basis of an electronic model with separable attractive interaction, the precursors at high temperature and strong coupling of the d-wave superc onducting state are investigated in the one-particle spectral function A(k, omega) and the total density of states rho(omega), with the use of the sel f-consistent t-matrix approximation. In the low-density region, it is found that a,gaplike structure at the Fermi level appears in A(k,omega) and rho( omega) above the superconducting transition temperature. It is shown that t he pseudogap energy scale is determined by the binding energy of the Cooper pair. [S0163-1829(99)00142-3].