Bergquist, J.C.Hulet, Randall G.Itano, Wayne M.Wineland, D.J.2015-03-302015-03-301986Bergquist, J.C., Hulet, Randall G., Itano, Wayne M., et al.. "Observation of Quantum Jumps in a Single Atom." <i>Physical Review Letters,</i> 57, no. 14 (1986) American Physical Society: 1699-1702. http://dx.doi.org/10.1103/PhysRevLett.57.1699.https://hdl.handle.net/1911/79434We detect the radiatively driven electric quadrupole transition to the metastable D522 state in a single, laser-cooled Hg II ion by monitoring the abrupt cessation of the fluorescence signal from the laser-excited S122→P122 first resonance line. When the ion "jumps" back from the metastable D state to the ground S state, the S→P resonance fluorescence signal immediately returns. The statistical properties of the quantum jumps are investigated; for example, photon antibunching in the emission from the D state is observed with 100% efficiency.engArticle is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.Journal articlehttp://dx.doi.org/10.1103/PhysRevLett.57.1699