Formation of Nuclear-Polarized Phases of H Atoms Embedded in Solid H_{2} Films. Academic Article uri icon

abstract

  • We report on an experimental observation of two phases of hydrogen atoms in solid H_{2} films at temperatures of 0.1-0.8K, characterized by a large enhancement of the nuclear spin polarization compared to that given by Boltzmann statistics (p=0.15 at T=0.15K). The first phase with p=0.35(5) is formed spontaneously during sample storage in a high magnetic field (B=4.6T). The second phase with an even higher nuclear polarization, p=0.75(7), can be achieved at T0.55K by repeating sequences of dynamic nuclear polarization followed by a system relaxation. Upon warming through the range 0.55-0.65K, the highly nuclear-polarized phase undergoes a phase transition to the spontaneously polarized phase which breaks down at T0.8K, and the nuclear polarization gradually converges to the Boltzmann distribution. We discuss possible scenarios for explaining the nature of the observed phenomena.

published proceedings

  • Phys Rev Lett

author list (cited authors)

  • Sheludiakov, S., McColgan, P. T., Lee, D. M., Khmelenko, V. V., Jrvinen, J., Ahokas, J., & Vasiliev, S.

publication date

  • January 1, 2019 11:11 AM