Entangled multiplet by angular momentum addition
  We present the visible entangled states of 4-qubit system which can be observed easily in physical laboratories. This was motivated from the fact that the entangled state of 2-qubit system comes from singlet and triplet states which are constructed through the angular momentum addition formalism. We show that 4-qubit system has the new entangled states different from GHZ or W types entangled states 
Hyuk-jae Lee, Sung Dahm Oh, Doyeol Ahn