Keywords
NMR, EPR, Magnetic Dipole Moment, Electric Quadrupole Moment, Multipole Moments, Lie Group
Abstract
To accurately solve the general nuclear spin state function in Nuclear Magnetic Resonance (NMR), a rotation wave approach was employed, allowing the reference frame to rotate in sync with the oscillating magnetic field. The spin state system was analogously treated as a Rubik's Cube, ensuring the diagonalization of only the time-dependent part of the state function. Although Gottfried's equation (1966) aligns with transitions between specific spin states m and m′, his second rotation contradicts the conservation of angular momentum, resulting in inaccuracies for spin states with initial phase shifts or entangled states. Contrarily, Schwinger (1937) efficiently computed the coefficients for each spin state in a frequency range opposite to the Larmor frequency, using an unorthodox approach in quantum mechanics, which unfortunately led to the oversight of his work in subsequent citations. This methodology was also applied to derive the general electron spin state function in Nuclear Magnetic Resonance (NMR) and Electron Paramagnetic Resonance (EPR), enabling the construction of a doubly rotated ground state for time-dependent perturbation theory. This was particularly relevant as the Hamiltonians for magnetic dipole, electric quadrupole, and magnetic octupole moments incorporate powers of I · J terms, necessitating the calculation of sub-state energy levels for perturbation, including those of molecules 14N7 and 7Li3. Furthermore, the study expanded to the general Lie group for 3D rotations along three linearly independent axes, resulting in 12 distinct methods to achieve rotations in any arbitrary direction using these axes, yielding wave function with only one spin operator in each exponent. The ongoing research is now concentrated on generating NMR spectra for 14N7 in amino acids, furthering the understanding of nuclear spin dynamics in complex molecular systems.
Completion Date
2024
Semester
Spring
Committee Chair
Klemm, Richard
Degree
Doctor of Philosophy (Ph.D.)
College
College of Sciences
Department
Physics
Degree Program
Physics
Format
application/pdf
Identifier
DP0028324
URL
https://purls.library.ucf.edu/go/DP0028324
Language
English
Rights
In copyright
Release Date
May 2024
Length of Campus-only Access
None
Access Status
Doctoral Dissertation (Open Access)
Campus Location
Orlando (Main) Campus
STARS Citation
Liu, Zhichen, "Advancements in Nuclear Magnetic Resonance, Electron Paramagnetic Resonance, Multipole Moments, and Lie Group Proprieties" (2024). Graduate Thesis and Dissertation 2023-2024. 155.
https://stars.library.ucf.edu/etd2023/155
Accessibility Status
Meets minimum standards for ETDs/HUTs