Soliton-Like Spin State in the A-Like Phase of 3He in Anisotropic Aerogel
Abstract
We have found a new stable spin state in the A-like phase of superfluid 3He confined to intrinsically anisotropic aerogel. The state can be formed by radiofrequency excitation applied while cooling through the superfluid transition temperature and its NMR properties are different from the standard A-like phase obtained in the limit of very small excitation. It is possible that this new state is formed by textural domain walls pinned by aerogel.

Stability of the axial phase of superfluid He3 in aerogel with globally anisotropic scattering
It has been suggested that anisotropic quasiparticle scattering will stabilize anisotropic phases of superfluid $^{3}\mathrm{He}$ 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 $^{3}\mathrm{He}$. Here, we present measurements of the phase diagram of superfluid $^{3}\mathrm{He}$ 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.
Evaluation of Lapping Grains based on Shape Characteristics.
The shape and size of abrasive grains during lapping varies complicately and irregularly. In this study, the aspect ratio of grain size and the fractal dimension of the grain external form were used as shape characteristics of grain in order to evaluate grains with lapping time. The results obtained are summarized as follows : (1)The fractal dimension increases due to microscopic fracture and decreases due to macroscopic fracture or attritious wear. (2)The aspect ratio and the fractal dimension, which are grain shape characteristicsis of the macroscopic shape and the microscopic surface complication of grain respectively, can be used for evaluating grain shape variation during lapping.