Progress Towards Measuring the Nuclear Spin Coherence of Molecules in Solid Parahydrogen

Prior work has shown that alkali atoms trapped in solid parahydrogen exhibit long electron spin coherence times [Physical Review A 100, 063419 (2019)]. Likewise, previous experiments have shown that the nuclear spin coherence of HD molecules in solid parahydrogen matrices was limited by the presence of orthohydrogen impurities [Journal of Low Temperature Physics 45, 167 (1981)]. We have demonstrated the ability to grow solid hydrogen samples with orthohydrogen fractions that are orders-of-magnitude lower than this prior work [Review of Scientific Instruments 92, 073202 (2021)]. The objective of our current research is to use NMR techniques to measure the nuclear spin coherence times of molecules trapped in these high-purity parahydrogen matrices. If, as expected from prior work, long coherence times are achieved, this would be of interest for quantum sensing and fundamental physics measurements. Construction of an apparatus capable of measuring nuclear spin coherence times and our progress towards this goal will be discussed.