Preparation of two-particle total hyperfine spin singlet states via   spin-changing dynamics
  We present our proposals for generating total hyperfine spin zero state for two f=1 or two f=2 particles, starting from initial unentangled states. We show that our goal can be achieved by exploiting spin changing dynamics and quadratic Zeeman shifts with realistic choices of external magnetic fields and evolution time intervals. 
Chao-Chun Huang, M.-S. Chang and S.-K. Yip
cond-mat.quant-gas