Competition between antiferromagnetism and superconductivity in a doped Hubbard model with anisotropic interaction

The competition between antiferromagnetism and superconductivity is one of the central questions in research involving strongly correlated systems. In this paper, we utilize a double-layer model containing Hubbard interaction and interlayer Heisenberg interaction to reveal their competition. This model is free of the sign problem under certain conditions, and we perform projector quantum Monte Carlo simulations to extract the ground-state correlations of magnetism and superconductivity. Our results show that the superconductivity emerges when the antiferromagnetism is suppressed by tuning the filling or the anisotropy of the interlayer Heisenberg interaction. This model can be seen as an analog of unconventional superconductors and may help us to understand the transition from an antiferromagnetic insulator to a superconductor.