Studies of nuclear polarization of hydrogen atoms embedded in solid molecular hydrogen and hydrogen deuteride films

Abstract

We report on an electron-spin resonance study of nuclear polarization of hydrogen atoms embedded in solid H2 and HD films at temperatures 0.1–1.5 K and in a high magnetic field of 4.6 T. Similar to our previous work [Phys. Rev. Lett. 122, 225301 (2019)], we observed a build-up of the spontaneously ( p ≃ 0.35 ) and highly ( p ≃ 0.75 ) nuclear polarized phases of H atoms in the as-deposited H2 films. However, we did not obtain an enhanced nuclear polarization of H atoms in the regions of their small local concentration. We also failed to observe enhanced nuclear polarization for H atoms in the annealed H2 films as well as in the as-deposited HD sample. These observations tend to support our previous explanation for the build-up of high nuclear polarization due to the formation of weakly-bound triplet H2 molecules.We report on an electron-spin resonance study of nuclear polarization of hydrogen atoms embedded in solid H2 and HD films at temperatures 0.1–1.5 K and in a high magnetic field of 4.6 T. Similar to our previous work [Phys. Rev. Lett. 122, 225301 (2019)], we observed a build-up of the spontaneously ( p ≃ 0.35 ) and highly ( p ≃ 0.75 ) nuclear polarized phases of H atoms in the as-deposited H2 films. However, we did not obtain an enhanced nuclear polarization of H atoms in the regions of their small local concentration. We also failed to observe enhanced nuclear polarization for H atoms in the annealed H2 films as well as in the as-deposited HD sample. These observations tend to support our previous explanation for the build-up of high nuclear polarization due to the formation of weakly-bound triplet H2 molecules.