  This letter is devoted to the optimization of the Cooper pair splitting
efficiency in a Y-shaped junction. The latter consists of two quantum dots, one
superconducting and two normal leads. We tailor the bias in the two normal
leads such that the Cooper pairs leaving the superconductor are split up
resulting in entangled electrons, one on each quantum dot. We are able to
achieve a splitting efficiency of more than 99% which is significantly better
than the efficiencies obtained in experiments so far.
