Interpretation of Recent Results on He 3 below 3 mK: A New Liquid Phase?

It is demonstrated that recent NMR results in $^{3}\mathrm{He}$ indicate that at 2.65 mK, the liquid makes a second-order transition to a phase in which the "spin-orbit" symmetry is spontaneously broken. The hypothesis that this phase is a BCS-type phase in which pairs form with $l$ odd, $S=1$, ${S}_{z}=\ifmmode\pm\else\textpm\fi{}1$ leads to reasonable agreement with both NMR and thermodynamic data, but involves some difficulties as to stability.