We present results for quantum Monte Carlo simulations of the quadrupolar fluctuation model of high-temperature superconductivity. The simulations focused on measurement of the pairing susceptibility in various interesting pairing channels (on-site, nearest-neighbor, and second-nearest-neighbor s- and d-wave pairing). The lattice was 4×4 in the oxygen sites, with eight copper sites bearing quadrupole moments. Exchange of these quadrupolar fluctuations may lead to attraction between oxygen holes. As in weak-coupling theory, we find (i) favorable tendencies towards second-nearest-neighbor s- and d-wave filling, with larger doping favoring d-wave symmetry; (ii) a nonmonotonic dependence of the pairing tendencies upon the on-site quadrupole level splitting; and (iii) a strong suppression of all nearest-neighbor pairing.

• Received 9 July 1990

DOI:https://doi.org/10.1103/PhysRevB.42.7960