Identification of Superfluid Phases of 3He in Uniformly Isotropic 98.2% Aerogel

Authors :: Pollanen, J.
Li, J. I. A.
Collett, C. A.
Gannon, W. J.
Halperin, W. P.
Publication Year :: 2011
Abstract: Superfluid 3He confined to high porosity silica aerogel is the paradigm system for understanding impurity effects in unconventional superconductors. However, a crucial first step has been elusive; exact identification of the microscopic states of the superfluid in the presence of quenched disorder. Using a new class of highly uniform aerogel materials, we report pulsed nuclear magnetic resonance experiments that demonstrate definitively that the two observed superfluid states in aerogel are impure versions of the isotropic and axial p-wave states. The theoretically predicted destruction of long-range orbital order (Larkin-Imry Ma effect) in the impure axial state is not observed.<br />Comment: 4 pages, 5 figures, to appear in Phys. Rev. Lett