Experimental demonstration of ground state laser cooling with electromagnetically induced transparency

Ground state laser cooling of a single trapped Ca+ ion is achieved with a t echnique which tailors the absorption profile for the cooling laser by expl oiting electromagnetically induced transparency. Using the Zeeman structure of the S-1/2 to P-1/2 dipole transition we achieve up to 90% ground state probability. The new method is robust, easy to implement, and proves partic ularly useful for cooling several motional degrees of freedom simultaneousl y, which is of great practical importance for the implementation of quantum logic schemes with trapped ions.