Contrasting mechanical anisotropies of the superfluid 3He phases in aerogel

Phys Rev Lett. 2007 Feb 16;98(7):075302. doi: 10.1103/PhysRevLett.98.075302. Epub 2007 Feb 14.

Abstract

There has been much recent interest in how impurity scattering may affect the phases of the p-wave superfluid 3He. Impurities may be added to the otherwise absolutely pure superfluid by immersing it in aerogel. Some predictions suggest that impurity scattering may destroy orientational order and force all of the superfluid phases to have an isotropic superfluid density. In contrast to this, we present experimental data showing that the response of the A-like phase to superfluid flow is highly anisotropic, revealing a texture that is easily modified by flow.