Superconductivity in the Two-Dimensionalt−JModel

Using computational techniques, it is shown that pairing is a robust property of hole-doped antiferromagnetic insulators. In one dimension and for two-leg ladder systems, a BCS-like variational wave function with long-bond spin singlets and a Jastrow factor provides an accurate representation of the ground state of the $t-J$ model, even though strong quantum fluctuations destroy the off-diagonal superconducting long-range order in this case. However, in two dimensions it is argued—and numerically confirmed using several techniques, especially quantum Monte Carlo—that quantum fluctuations are not strong enough to suppress superconductivity.