Quantum Transition between an Antiferromagnetic Mott Insulator anddx2−y2Superconductor in Two Dimensions

We consider a Hubbard model on a square lattice with an additional interaction, $W$, which depends upon the square of the near-neighbor hopping. At half filling and a constant value of the Hubbard repulsion, increasing the strength of the interaction $W$ drives the system from an antiferromagnetic Mott insulator to a $d_{x^2{-y}^2}$ superconductor. This conclusion is reached on the basis of zero temperature quantum Monte Carlo simulations on lattice sizes up to $16\times 16$.