Nuclear spin coherence times of HD trapped in solid parahydrogen matrices
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Authors
Rollings, Alexandar
Issue Date
2025
Type
Dissertation
Language
en_US
Keywords
EDM , HD , Hydrogen Deuteride , NMR , Solid Parahydrogen , Solid State NMR
Alternative Title
Abstract
Solid parahydrogen is an appealing host material for nuclear-spin spectroscopy and precision measurements, providing a weakly interacting environment for embedded molecules, and a high degree of magnetic purity. While previous studies have demonstrated the potential of doped solid-parahydrogen matrices for high-resolution infrared spectroscopy, systematic measurements of nuclear spin coherence and relaxation across controlled impurity conditions remain limited. This dissertation describes the design, construction, and operation of an apparatus that addresses the need to improve existing coherence-time measurements. In this dissertation, we outline the scientific motivation for measuring nuclear spin coherence times. We then detail the apparatus we constructed, which integrates a two-stage orthohydrogen-to-parahydrogen converter, a cryogenic vapor-deposition system, and a high-field NMR spectrometer designed for coherent spin excitation and detection. Using this platform, we carry out free-induction decay spectroscopy, multi-Lorentzian lineshape analysis, spin-echo measurements, and longitudinal relaxation studies on parahydrogen samples doped with HD molecules. Across a range of sample conditions, we observe an improvement on transverse relaxation times over previous studies, and correspondingly measure long longitudinal relaxation. We probe samples with orthohydrogen fractions three orders of magnitude lower than in prior work. In low-impurity samples, the resulting spectral resolution is sufficient to resolve the $J$-coupling hyperfine structure in HD, demonstrating the capability of the apparatus to access narrow-linewidth features in parahydrogen solids. We conclude with a summary of coherence time results and a discussion of future efforts to improve our sensitivity. The platform developed in this work provides a foundation for future spectroscopy and precision-measurement experiments involving molecules in solid parahydrogen.