Spontaneous emission lifetime of a single trapped Ca(+) ion in a high finesse cavity.

We investigate the spontaneous emission lifetime of a single trapped (40)Ca+ ion placed at different positions in the vacuum standing wave inside a high finesse cavity which is stabilized to the atomic transition. The lifetime is measured by quantum state detection after pi-pulse excitation. The result for the natural lifetime of the D(5/2) metastable state of 1161(22) ms agrees, within 1 standard deviation, with the most precise published value. We observe a reduction of the spontaneous emission lifetime of approximately 15% in the node of the vacuum field.

Coupling a single atomic quantum bit to a high finesse optical cavity.

The quadrupole S(1/2)-D(5/2) optical transition of a single trapped Ca+ ion, well suited for encoding a quantum bit of information, is coherently coupled to the standing wave field of a high finesse cavity. The coupling is verified by observing the ion's response to both spatial and temporal variations of the intracavity field. We also achieve deterministic coupling of the cavity mode to the ion's vibrational state by selectively exciting vibrational state-changing transitions and by controlling the position of the ion in the standing wave field with nanometer precision.