Lattice-induced rapid formation of spin singlets in spin-1 spinor condensates

We experimentally demonstrate that combining a spinor Bose-Einstein condensate with cubic optical lattices significantly relaxes three strict constraints and enables a rapid generation of spin singlets using ultracold spin-1 atoms. Our observations confirm that spin singlets of spin-1 atoms are brought into experimentally accessible regions by two key lattice-modified parameters, which are the lattice-enhanced interatomic interactions and substantially reduced atom number in individual lattice sites. About 80 percent of atoms in the lattice-confined spin-1 spinor condensate are found to form spin singlets, after the atoms cross first-order superfluid to Mott-insulator phase transitions in an ideal lattice ramp sequence. In addition, we develop a phenomenological model that well describes our observations without adjustable parameters.