High-purity solid parahydrogen

Abstract

Alkali atoms trapped in solid hydrogen matrices have demonstrated ultralong electron spin coherence times, and are promising as quantum sensors. Their spin coherence is limited by magnetic noise from naturally-occurring orthohydrogen molecules in the parahydrogen matrix. In the gas phase, the orthohydrogen component of hydrogen can be converted to parahydrogen by flowing it over a catalyst held at cryogenic temperatures, with lower temperatures giving a lower orthohydrogen fraction. In this work, we use a single cryostat to reduce the orthohydrogen fraction of hydrogen gas and grow a solid matrix from the resulting high-purity parahydrogen. We demonstrate operation of the catalyst down to a temperature of 8 K, and we spectroscopically verify that orthohydrogen impurities in the resulting solid are at a level < 1e-6. We also find that, at sufficiently low temperatures, the cryogenic catalyst provides isotopic purification, reducing the HD fraction.

7 pages, 8 figures

References in corpus (6)

• Sensitivity Optimization for NV-Diamond Magnetometry
• Sticking coefficient of hydrogen and deuterium on silicates under interstellar conditions
• Gas temperature dependent sticking of hydrogen on cold amorphous water ice surfaces of interstellar interest
• Ultralong spin coherence times for rubidium atoms in solid parahydrogen via dynamical decoupling
• Spin coherence and optical properties of alkali-metal atoms in solid parahydrogen
• Enhanced spin coherence of rubidium atoms in solid parahydrogen

Cited by in corpus (4)

• Equation of state of solid parahydrogen using ab initio two-body and three-body interaction potentials
• Electron thermalization length in solid para-hydrogen at low-temperature
• Path-integral Monte Carlo simulations of solid parahydrogen using two-body, three-body, and four-body ab initio interaction potential energy surfaces
• Long nuclear spin coherence times for molecules trapped in high-purity solid parahydrogen