Graduation date: 1993

Thesis (Ph. D.)--Oregon Graduate Center, 1982.

Thesis (Ph. D.)--Oregon Graduate Center, 1980.

This thesis comprises a computer analysis of NMR-determined interatomic distance in strontium formate dihydrate. The computer program is designed to locate the hydrogen atoms associated with the water molecules in strontium formate dihydrate. The bond length of the oxygen-hydrogen bond is assumed to be fixed. The program varies the hydrogen separation, plotting total proton interaction against the hydrogen separation distance. Using Van Vleck's second moment theory, the hydrogen-hydrogen distances were determined.. The value of the second moment of the NMR absorption curve is 24.6 gauss2, obtained from investigation by Dr. D. E. Koltenbah. The result of this thesis is that the proton separation is 1.47± .02 A. This result is found to be close enough to other studies to conclude that the program analysis is essentially sound.

Thesis (M.S.)--Rutgers University, 2009. / "Graduate Program in Physics and Astronomy." Includes bibliographical references (p. 83-87).

Since the discovery of superconductivity in Sr2RuO4, there has been intense research interest and efforts on its unconventional pairing symmetry. Although its normal state can be qualitatively described as a quasi-two-dimensional Fermi liquid, surprisingly, Sr2RuO4 turns out to be the prime candidate of the chiral p + ip superconductor, analogous to 3He-A. Such a state is of great interest surrounding, since under a certain conditions it hosts such exotic objects as half-quantum vortices and Majorana bound states, one possible route to an enigmatic quantum computer. Nevertheless, although it is well established now that this superconducting state has odd-parity, and most likely breaks time-reversal symmetry, the negative result on the search of edge current is one of the critical challenges to its chiral p-wave order. These serious discrepancies have even triggered a debate on the primary source of its superconductivity. Motivated by this debate, in this thesis we propose two independent methods to resolve this controversy via “smoking-gun" experiments. First, the vortex structure within the single-band and two-band models is studied within a mean-field theory. The pattern of the local density-of-state at zero bias shows significant anisotropy in the two-band model, while it is nearly isotropic in the single-band case. Also, the spin lattice relaxation rate at the vortex site is greatly enhanced in the single-band case but not in the two-band scenario. These important distinctions stem from the topology of different Fermi surfaces, and can be tested by using standard probes such as scanning tunneling microscope and nuclear magnetic resonance. In the second proposal, we focus on the two-band scenario, and apply a renormalization group theory to explain the form of spin density wave fluctuations. This theory not only reconciles the absence of long range spin density wave order with strongly enhanced fluctuations, but also unveils the mutual exclusion of these fluctuations and p-wave superconducting pairing. Such an exclusion is reflected in the suppression of the spin-spin correlation function at low energies, which can be measured in the inelastic neutron scattering experiment. This suppression, if not observed experimentally, would be a critical challenge to the two-band model, and an indirect but strong support to the assignment of the single γ-band as the primary source of the unconventional pairing. / published_or_final_version / Physics / Doctoral / Doctor of Philosophy

No description available.

No description available.

The objective of this thesis is to construct a measurement system, measuring Radiation from Strontium with mass number 90 ( 90 Sr). The absorbed beta particle has a kinetic energy of 546 keV. The constructed scanning system makes it possible to sweep over a larger area than the actual Silicon detector. The used detector has an area of 1cm 2 . [1] A Si detector is connected to an electronic read out circuit. The Arduino microcontroller reads the output of the circuit and translates it to digital signals and sends them to a personal computer. After one signal has been read, Arduino will discharge the peak detector in the circuit to read another signal. The Arduino control software Processing will receive and process the digital output from Arduino. There will be three windows showing the number of counts from Arduino, the movement of the steering engine controlled by Thorlabs, and the sum counts of every position where the detector is.

Thesis (Ph. D.)--University of Hong Kong, 2007. / Also available in print.