Correlation-induced d-wave pairing in a quantum dot square lattice

We consider an electrostatically induced square lattice of quantum dots and study the role of electron-electron correlations in the resulting electronic features of the system. We utilize the Wannier functions methodology to construct a Hamiltonian for interacting fermions, and find that the change of the depth of the quantum dot confining potential results in a transition from a moderately, to strongly correlated regime of the system. We obtain the approximate ground state by means of the variational Monte Carlo method for a wide range of dopings. The values of microscopic parameters, charge gap, as well as spin-and pair-correlation functions obtained in the strongly correlated regime signify the presence of antiferromagnetic spin ordering and the realization of the Mott insulator phase. Moreover, we report on a two-dome structure of the emerging d-wave paired state residing on both sides of the half-filled case. The obtained results are discussed in view of the well-known family of unconventional superconducting materials, such as copper-based compounds.