Stability of the axial phase of superfluid 3He in aerogel with globally anisotropic scattering

It has been suggested that anisotropic quasiparticle scattering will stabilize anisotropic phases of superfluid He-3 contained within a highly porous silica aerogel. For example, global anisotropy introduced via uniaxial compression of aerogel might stabilize the axial state, which is called the A-phase in bulk superfluid He-3. Here, we present measurements of the phase diagram of superfluid He-3 in a 98% porous silica aerogel by using transverse acoustic impedance methods. We show that uniaxial compression of the aerogel by 17% does not stabilize an axial phase.