NMR quantum gate factorization through canonical cosets
  The block canonical coset decomposition is developed as a universal algorithmic tool to synthesize n-qubit quantum gates out of experimentally realizable NMR elements. The two-, three-, and four-qubit quantum Fourier transformations are worked out as examples. The proposed decomposition bridges the state of the art numerical analysis with NMR quantum gate synthesis. 
Renan Cabrera, Denys I. Bondar, Herschel A. Rabitz
quant-ph