Doped valence-bond solid and superconductivity on the Shastry-Sutherland lattice

Motivated by recent experiments on SrCu2(BO3)(2), we investigate the ground states of the doped Mott insulator on the Shastry-Sutherland lattice. To provide a unified theoretical framework for both the valence-bond solid state found in undoped SrCu2(BO3)(2) and the doped counterpart being pursued in on-going experiments, we analyze the t-J-V model via the bond-operator formulation. It is found that superconducting states emerge upon doping with their properties crucially depending on the underlying valence-bond order. Implications to future experiments are discussed.