Thesis (Ph. D.)--Institute of Paper Chemistry, 1977. / Includes bibliographical references (p. 257-261).

Thesis (Ph. D.)--University of Oregon, 2002. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 187-198). Also available for download via the World Wide Web; free to University of Oregon users.

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No description available.

In this thesis, I report on experiments with cold 85Rb atoms in a far-detuned one-dimensional optical lattice. These experiments are focused on creating efficient coupling between the quantized vibrational states of atoms in the optical lattice, on controlling and maintaining coherence between the vibrational states, and on developing a spectroscopy method to characterize the decay of coherence. First, I present an experimental study of the application of simple and compound pulses consisting of time-dependent spatial translations to coupling vibrational states of ultracold 85Rb atoms in the optical lattice. Experimental results show that a square pulse consisting of lattice displacements and a delay is more efficient than single-step and Gaussian pulses. The square pulse can be seen as an example of coherent control. Numerical calculations are in strong agreement with the experimental results. In addition, it is shown numerically that the vibrational state coupling due to such lattice manipulations is more efficient in shallow lattices than in deep lattices, in which the coupling probability approaches the harmonic oscillator limit. Next, the effectiveness of these pulses in reviving oscillations of atoms in vibrational superposition states using a pulse-echo technique is examined. Experimental results show that the square and Gaussian pulses result in higher echo amplitudes than the single-step pulse. These echo amplitudes are an order of magnitude larger than the echo amplitudes observed previously for the motional states of atoms in optical lattices. With the aim of the optimized square echo pulse, echo amplitude is measured at much longer times, where a surprising coherence freeze (plateau) is observed. To investigate mechanisms responsible for the observed echo decay and the coherence freeze, we developed a new two-dimensional pump-probe spectroscopy technique to monitor the evolution of frequency-frequency correlations in the system, a necessary input for understanding the decay of coherence. Through this 2D technique, we have characterized the temporal decay of frequency memory and through our simulations we find that coherence freeze is related to the shape of this memory loss function. This technique is general in that it can be applied in a variety of quantum information candidate systems to probe the nature of their decoherence.

In this thesis, I report on experiments with cold 85Rb atoms in a far-detuned one-dimensional optical lattice. These experiments are focused on creating efficient coupling between the quantized vibrational states of atoms in the optical lattice, on controlling and maintaining coherence between the vibrational states, and on developing a spectroscopy method to characterize the decay of coherence. First, I present an experimental study of the application of simple and compound pulses consisting of time-dependent spatial translations to coupling vibrational states of ultracold 85Rb atoms in the optical lattice. Experimental results show that a square pulse consisting of lattice displacements and a delay is more efficient than single-step and Gaussian pulses. The square pulse can be seen as an example of coherent control. Numerical calculations are in strong agreement with the experimental results. In addition, it is shown numerically that the vibrational state coupling due to such lattice manipulations is more efficient in shallow lattices than in deep lattices, in which the coupling probability approaches the harmonic oscillator limit. Next, the effectiveness of these pulses in reviving oscillations of atoms in vibrational superposition states using a pulse-echo technique is examined. Experimental results show that the square and Gaussian pulses result in higher echo amplitudes than the single-step pulse. These echo amplitudes are an order of magnitude larger than the echo amplitudes observed previously for the motional states of atoms in optical lattices. With the aim of the optimized square echo pulse, echo amplitude is measured at much longer times, where a surprising coherence freeze (plateau) is observed. To investigate mechanisms responsible for the observed echo decay and the coherence freeze, we developed a new two-dimensional pump-probe spectroscopy technique to monitor the evolution of frequency-frequency correlations in the system, a necessary input for understanding the decay of coherence. Through this 2D technique, we have characterized the temporal decay of frequency memory and through our simulations we find that coherence freeze is related to the shape of this memory loss function. This technique is general in that it can be applied in a variety of quantum information candidate systems to probe the nature of their decoherence.

No description available.

The molecular conformations, potential energy functions and vibrational spectra of several cyclic molecules have been investigated by ab initio and density functional theory calculations and by infrared and Raman spectroscopy. The ab initio computations of 3-cyclopenten-1-ol predict that its lowest energy conformer has a weak pi-type intramolecular hydrogen bonding. The three other conformers lie 301 to 411 cm^-1 higher in energy. The infrared and Raman spectra of this molecule confirm the presence of the four conformers. The energy difference between the two conformers of lowest energy was also determined from the experimental spectroscopic data and was found to be 435 plus/minus 160 cm^-1, in reasonable agreement with the ab initio computations results. Ab initio calculations for cyclopentane and d1, 1,1-d2, 1,1,2,2,3,3-d6, and d10 isotopomers confirm cyclopentane confirmed that has twist and bent structures and that these differ in energy by less than 10 cm^-1. The bending angle is 41.5 degrees and the twisting angle is 43.2 degrees. A complete vibrational assignment for each of the isotopomers was achieved. Ab initio calculations were also carried out for methylcyclopropane, cyclopropylsilane, cylopropylgermane, cyclopropylamine, cyclopropanethiol and cyclopropanol. The structure and the potential energy function for internal rotation was calculated for each and compared to available experimental results determined from infrared and Raman spectra. The calculated barriers to internal rotation agree very well with the experimental data. The structures, relative energies, and frequencies for the lowest energy vibrations of the twisted, bent, and planar forms of cyclohexene and four of its oxygen analogs were calculated and compared to experimental results. The calculated structural data agree very well with that from the microwave work, but the computed barriers are somewhat lower than those based on far-infrared data. 4-Silaspiro-(3,3)-heptane possesses two four-membered rings, each puckered with and angle of 34 degrees. The molecule possesses a two-dimensional ring-puckering potential energy surface with four equivalent minima. The ab initio calculations predict a barrier to planarity of each ring of 582 cm^-1 while the energy of the structure with both rings planar is 1220 cm^-1 higher. The calculated infrared and Raman spectra were compared to those previously published, and the agreement is excellent.

Thesis (M. Sc.)--University of Adelaide, Dept. of Physics, 1985. / Includes bibliographical references (leaves 76-78).

Rozprawa habilitacyjna--University of Warsaw. / Bibliography: p. [146]-155.