Wiess School of Natural Sciences

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Lecture notes in mathematics: an elementary approach to bounded symmetric domains
(Rice University, 1969) Koecher, Max; Jones, B. Frank; Houston, Tex. : Rice University
Lecture notes in mathematics: rudiments of Riemann surfaces
(Rice University, 1971) Jones, B. Frank; Houston, Tex. : Rice University
Galvanomagnetic measurements of annealing in deformed aluminium
(Wiley, 1974) Rau, C.
Origin and Structure of the Quasi-Landau Resonances
(American Physical Society, 1980) Castro, Jarbas C.; Zimmerman, Myron L.; Hulet, Randall G.; Kleppner, Daniel; Freeman, Richard R.
Highly resolved spectra are presented which show how the low-magnetic-field energy-level structure of a single-electron atom gives rise to the quasi-Landau resonances as the field is increased. Data from the strong-mixing region where electric and magnetic forces are comparable reveal that evenly spaced energy levels are a general feature, irrespective of parity and magnetic quantum number of the states. The quasi-Landau resonances emerge by a concentration of oscillator strength into a single level of each term.
Electron-Spin Polarization at Single-Crystalline Cr and Ni Surfaces Determined with Electron-Capture Spectroscopy
(American Physical Society, 1981) Rau, C.; Eichner, S.
The spin polarization P of electrons at Cr and Ni surfaces is measured with electron-capture spectroscopy. With use of one-electron capture at magnetized Cr(100)-c(2×2) surfaces at 293 K (TN=310 K), P values up to -18% are found revealing ferromagnetic order at this surface. Utilizing two-electron capture at demagnetized Ni surfaces we find at 293 K (TC=631 K) |P|=94% for Ni(110), |P|=72% for Ni(100), |P|=47% for Ni(111), and |P|=14% for Ni(120). There is evidence that "local" ferromagnetic order at Ni surfaces exists even at 2TC.
Rydberg Atoms in "Circular" States
(American Physical Society, 1983) Hulet, Randall G.; Kleppner, Daniel
The population of a beam of lithium atoms has been transferred from a low angular momentum Rydberg state to a state with |m|=n−1, with nearly 100% efficiency. Selective field ionization is employed to detect the high |m| state. Transfer occurs by a series of adiabatic rapid passages; it can also occur by a single multiphoton process.
Comparisons of approximate bases for hydrogen in a magnetic field
(American Physical Society, 1983) Zimmerman, Myron L.; Hulet, Randall G.; Kleppner, Daniel
Solutions to the diamagnetic Hamiltonian for Rydberg states of hydrogen are studied in the low-magnetic-field regime where term mixing can be ignored. Several recently proposed approximate bases are compared by calculating the overlap integrals with an accurate numerically generated basis.
X-ray laser implementation by means of a strong source of high-spin metastable atoms
(American Physical Society, 1983) Helman, J.S.; Rau, C.; Bunge, C.F.
High-spin metastable atomic beams of high density and extremely small divergence can be produced by electron capture during grazing-angle scattering of ion beams at ferromagnetic surfaces. This can be used to generate a long-lived reservoir of Li 1s2s2p P5204 with enough density of metastables so that after laser-induced transfer to Li 1s2p2P2 strong lasing at 207 Å should occur. This novel technique can also be used to produce a variety of other metastables known as potential candidates for lasing at shorter wavelengths.
Inhibited Spontaneous Emission by a Rydberg Atom
(American Physical Society, 1985) Hulet, Randall G.; Hilfer, Eric S.; Kleppner, Daniel
Spontaneous radiation by an atom in a Rydberg state has been inhibited by use of parallel conducting planes to eliminate the vacuum modes at the transition frequency. Spontaneous emission is observed to "turn off" abruptly at the cutoff frequency of the waveguidelike structure and the natural lifetime is measured to increase by a factor of at least 20.
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.
Ferromagnetic order at surfaces of ultrathin epitaxial fcc γ-Fe(111)p(11) films on Cu(111)
(American Physical Society, 1986) Rau, C.; Schneider, C.; Xing, G.; Jamison, K.
Electron-capture spectroscopy has been used to investigate long-ranged and short-ranged two-dimensional magnetic order at free (uncoated) surfaces of homogeneous (island-free), ultrathin fcc γ-Fe(111)(1×1) films pseudomorphically deposited on Cu(111) substrate crystals. At 298 K, the electron-spin polarization at the surface of a four-monolayer thin fcc Fe film amounts to +16%, directly revealing the existence of long-ranged ferromagnetic order. There is evidence that short-ranged ferromagnetic order still exists at 400 K at free surfaces of two and one-monolayer thin fcc Fe films.
Evidence for ferromagnetic order at gadolinium surfaces above the bulk Curie temperature
(American Physical Society, 1986) Rau, C.; Eichner, S.
The electron-spin polarization P at the topmost layer of atomically clean, magnetized gadolinium (Gd) surfaces is measured by using electron capture spectroscopy. P varies almost linearly with temperature between 160 K (P=-42%) and 315 K (P=0). It is found that the surface Curie temperature TCs is far above—lying near 310 K—the bulk Curie temperature TCb=292.5 K, indicating uniaxial anisotropic magnetic exchange interactions at the topmost surface layer of Gd.
Ferromagnetic Order at (100) p(1×1) Surfaces of Bulk Paramagnetic Vanadium
(American Physical Society, 1986) Rau, C.; Liu, C.; Schmalzbauer, A.; Xing, G.
Electron-capture spectroscopy has been used to investigate magnetic order at the topmost atomic layer of atomically clean and flat (100) surfaces of bulk paramagnetic vanadium. From low-energy electron diffraction measurements, we find a p(1×1) surface structure. At 300 K, the long-ranged electron-spin polarization amounts to ∼34%, clearly demonstrating the existence of ferromagnetic order at the V(100) p(1×1) surface. With increasing temperature, the electron-spin polarization decreases almost linearly and disappears at a surface Curie temperature TCs≈540 K.
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.
Surface magnetization of Gd at the bulk Curie temperature
(American Physical Society, 1987) Rau, C.; Robert, M.
Electron-capture spectroscopy is used to study the long-ranged surface ferromagnetic order of Gd in the neighborhood of the bulk Curie temperature TCbulk at which, unlike bulk ferromagnetic order, it does not vanish. The surface magnetization, together with its first temperature derivative, is found to be a continuous function of temperature at TCbulk and, as temperature is varied, the surface magnetization is found to depart linearly from the nonzero value it assumes at TCbulk, with critical exponents x+=1.00±0.03 (T>TCbulk) and x−=1.00 ±0.01 (T
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.
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.
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.
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.
The Teichmüller Theory of Harmonic Maps
(Journal of Differential Geometry, 1989) Wolf, Michael

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