Realization of Fredkin Gate by Three Transition Pulses in NMR Quantum   Information Processor
  The three-qubit conditional swap gate(Fredkin gate) is a universal gate that can be used to create any logic circuit and has many direct usages. In this paper, we experimentally realized Fredkin gate with only three transition pulses in solution of alanine. It appears that no experimental realization of Fredkin gate with fewer pulses has yet been reported up to now. In addition, the simple structure of our scheme makes it easy to be implemented in experiments. 
Xue Fei, Du Jiangfeng, Shi Mingjun, Zhou Xianyi, Han Rongdian, Wu   Jihui