Longitudinal Spin Relaxation of Optically Pumped Rubidium Atoms in Solid Parahydrogen.
We have grown crystals of solid parahydrogen using a single closed-cycle cryostat. We have doped the crystals with rubidium atoms at densities on the order of 10^{17}  cm^{-3} and used optical pumping to polarize the spin state of the implanted atoms. The optical spectrum of the rubidium atoms shows larger broadening than previous work in which the rubidium was implanted in solid argon or neon. However, the optical pumping behavior is significantly improved, with both a larger optical pumping signal and a longer longitudinal relaxation time. The spin relaxation time shows a strong dependence on orthohydrogen impurity levels in the crystal, as well as the applied magnetic field. Current performance is comparable to state-of-the-art solid state systems at comparable spin densities, with potential for improvement at higher parahydrogen purities.
Department of Physics, University of Nevada, Reno, Nevada 89557, USA.
Sunil
S
Upadhyay
Department of Physics, University of Nevada, Reno, Nevada 89557, USA.
Andrew N
AN
Kanagin
Department of Physics, University of Nevada, Reno, Nevada 89557, USA.
Chase
C
Hartzell
Department of Physics, University of Nevada, Reno, Nevada 89557, USA.
Tim
T
Christy
Department of Physics, University of Nevada, Reno, Nevada 89557, USA.
W Patrick
WP
Arnott
Department of Chemistry, The University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada.
Takamasa
T
Momose
Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
David
D
Patterson
Department of Physics, University of Nevada, Reno, Nevada 89557, USA.
Jonathan D
JD
Weinstein