RAMAN-SCATTERING IN THE T-J MODEL WITH DOPING

We present the Raman spectrum at zero temperature of the t-J model with zero, one, and two holes. The calculation is exactly performed on a 4×4 lattice, and the symmetry of the Raman operator is B1g. Cumulants of the distribution are presented, and the static limit (t=0) is discussed. For zero hole we show that Lanczos results provide information of the same quality as series expansions. For one and two holes, the two-magnon peak reduces its energy and intensity with respect to half-filling, while spectral weight appears at high energies. We show the position of the two-magnon peak as a function of J/t and from there make predictions about Raman-scattering experiments at finite doping. © 1990 The American Physical Society.