Robust state preparation of a single trapped ion by adiabatic passage
  We report adiabatic passage experiments with a single trapped $^{40}$Ca$^+$ ion. By applying a frequency chirped laser pulse with a Gaussian amplitude envelope we reach a transfer efficiency of 0.990(10) on an optical transition from the electronic ground state S$_{1/2}$ to the metastable state D$_{5/2}$. This transfer method is shown to be insensitive to the accurate setting of laser parameters, and therefore is suitable as a robust tool for ion based quantum computing. 
Chr. Wunderlich, Th. Hannemann (National University of Ireland,   Maynooth, Co. Kildare, Ireland Present address: University...