  We show that laser assisted hopping of hard core bosons in a square optical
lattice can be described by an antiferromagnetic $J_{1}$-$J_{2}$ XY model with
tunable ratio of $J_{2}/J_{1}$. We numerically investigate the phase diagram of
the $J_{1}$-$J_{2}$ XY model using both the tensor network algorithm for
infinite systems and the exact diagonalization for small clusters and find
strong evidence that in the intermediate region around $% J_{2}/J_{1}\sim 0.5$,
there is a spin liquid phase with vanishing magnetization and valence bond
orders, which interconnects the Neel state on the $J_{2}\ll J_{1}$ side and the
stripe antiferromagnetic phase on the $% J_{2}\gg J_{1}$ side. This finding
opens up the possibility of studying the exotic spin liquid phase in a
realistic experimental system using ultracold atoms in an optical lattice.
