= Helium-3 A phase
{title2=$\mathbf d_A=\Delta\widehat{\mathbf d}(\widehat k_x+i\widehat k_y)$}
Take a real <unit vector> in spin space $\widehat{\mathbf d}$ and choose orthogonal orbital axes. The model has
$$
A_A=\Delta\widehat{\mathbf d}\,(1,i,0),\qquad
|\mathbf d_A|=\Delta\sqrt{\widehat k_x^2+\widehat k_y^2}
=\Delta|\sin\theta|.
$$
It vanishes at the two polar directions and is largest at the equator. The orbital factor changes sign when $\widehat{\mathbf k}$ is reversed, as required for the odd orbital part of <spin-triplet p-wave pairing>. Calling the phase A does not mean its <order parameter> is one real number.
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