Strong Orientational Effect of Stretched Aerogel on the He3 Order Parameter

Deformation of aerogel strongly modifies the orientation of the order parameter of superfluid He3 confined in aerogel. We used a radial squeezing of aerogel to keep the orbital angular momentum of the He3 Cooper pairs in the plane perpendicular to the magnetic field. We did not find strong evidence for a polar phase, with a nodal line along the equator of the Fermi surface, predicted to occur at large radial squeezing. Instead we observed He3-A with a clear experimental evidence of the destruction of the long-range order by random anisotropy—the Larkin-Imry-Ma effect. In He3-B we observed and identified new modes of NMR, which are impossible to obtain in bulk He3-B. One of these modes is characterized by a repulsive interaction between magnons, which is suitable for the magnon Bose-Einstein condensation.