Quantum phases in a doped mott insulator on the Shastry-Sutherland lattice

We propose the projected BCS wave function as the ground state for the doped Mott insulator SrCu2(BO3)(2) on the Shastry-Sutherland lattice. At half filling this wave function yields the exact ground state. Adding mobile charge carriers, we find a strong asymmetry between electron and hole doping. Upon electron doping an unusual metal with strong valence bond correlations forms. Hole doped systems are d-wave resonating valence bond superconductors in which superconductivity is strongly enhanced by the emergence of spatially varying plaquette bond order.