Schwinger boson symmetric spin liquids of Shastry-Sutherland model

Motivated by recent experimental and numerical evidences of deconfined quantum critical point and quantum spin-liquid states in spin-1/2 Heisenberg model on Shastry-Sutherland lattice, we studied possible symmetric spin liquid states and their proximate ordered states under Schwinger boson formalism. We found a symmetric gapped Z2 spin-liquid state for intermediate model parameter (J_1/J_2 between 0.66 and 0.71) under mean-field approximation. The Schwinger boson mean-field picture is partially supported by exact-diagonalization and self-consistent spin wave theory results.