Optimizing entangling quantum gates for physical systems
  Optimal control theory is a versatile tool that presents a route to significantly improving figures of merit for quantum information tasks. We combine it here with the geometric theory for local equivalence classes of two-qubit operations to derive an optimization algorithm that determines the best entangling two-qubit gate for a given physical setting. We demonstrate the power of this approach for trapped polar molecules and neutral atoms. 
M. M. M\"uller, D. M. Reich, M. Murphy, H. Yuan, J. Vala, K. B.   Whaley, T. Calarco, and C. P. Koch
quant-ph