Browsing by Author "Wineland, D.J."
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Item Laser-cooling limits and single-ion spectroscopy(American Physical Society, 1987) Wineland, D.J.; Itano, Wayne M.; Bergquist, J.C.; Hulet, Randall G.The limitations to the achievement of low kinetic energies for laser cooling of single ions confined in electromagnetic traps are discussed. Sideband cooling of an ion in an rf (Paul) trap is reexamined including the effects of finite laser bandwidth and the energy of the rf micromotion. The micromotion is the oscillatory motion of the ion at the same frequency as the rf voltage applied to the trap electrodes. Sideband cooling of ions in a Penning trap is examined for the first time. In both cases, cooling to the zero-point energy of the ion in the trap should be possible and a method for verifying this condition is suggested. The implications for high-resolution, high-accuracy spectroscopy are investigated. Under certain conditions, the uncertainty in the second-order Doppler shift may be significantly less than 1 part in 10?18.Item Observation of Quantum Jumps in a Single Atom(American Physical Society, 1986) Bergquist, J.C.; Hulet, Randall G.; Itano, Wayne M.; Wineland, D.J.We 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.Item Precise Optical Spectroscopy with Ion Traps(IOP, 1988) Itano, Wayne M.; Bergquist, J.C.; Hulet, Randall G.; Wineland, D.J.We have used stored ion methods to improve resolution and sensitivity in optical spectroscopy. Single atomic ions have been confined by electric and magnetic fields, cooled by laser radiation pressure to temperatures on the order of 1 mK, and probed spectroscopically with narrowband lasers. The absorption resonance of a single Hg+ ion has been observed by a decrease in the transmitted light intensity. An ultraviolet transition in Hg+ has been observed with a linewidth of only 30 kHz. Quantum jumps to and from metastable levels of Hg+ have been observed and used to determine radiative decay rates and to infer the existence of photon antibunching. Quantum jumps have also been observed in single Mg+ ions.Item Precise test of quantum jump theory(American Physical Society, 1988) Hulet, Randall G.; Wineland, D.J.; Bergquist, J.C.; Itano, Wayne M.Quantum jumps due solely to spontaneous Raman scattering between the Zeeman sublevels of a single Mg+24 ion have been observed in the fluorescence emitted by the ion. A theory of quantum jumps for this system predicts that coherences between excited levels cause the ratio of the mean duration of the "fluorescence-on periods" to the mean duration of the "fluorescence-off periods" to be independent of laser intensity. The measured value agrees with the predicted one to within the measurement precision of 2%. The distribution of the durations of the off periods also agrees with theory.Item Quantum jumps via spontaneous Raman scattering(American Physical Society, 1987) Hulet, Randall G.; Wineland, D.J.A single laser, which is used to induce and detect spontaneous Raman transitions, can be used to observe quantum jumps in a single atom. The population dynamics of a particular system, consisting of two S1/22 ground-state levels and four P3/22 excited-state levels split by a magnetic field, is analyzed for a laser tuned near a particular transition. We find that the statistics of the fluorescence emitted by this system are described by the same formalism developed for the three-level V configuration irradiated by two light sources. Over a wide range of observation times, the fluorescence intensity will be two valued, either off or on, as has been verified for the V configuration. Some surprising and elegant features of this new system are described.Item Radiative Decay Rates in Hg+ from Observations of Quantum Jumps in a Single Ion(American Physical Society, 1987) Itano, Wayne M.; Bergquist, J.C.; Hulet, Randall G.; Wineland, D.J.Radiative decay rates connecting the lowest four energy levels of Hg+198 have been derived solely from an analysis of the fluctuations (quantum jumps) of the laser-induced fluorescence of the 194-nm first resonance transition of a single ion confined in a Paul trap. The natural linewidth of the 194-nm first resonance transition was also measured. The measured decay rates and branching ratios are in satisfactory agreement with theory.