Unresolved problems in the superfluid phases of [sup 3]He

The early studies of the superfluid phases of [sup 3]He were marked by often spectacular agreements between theoretical predictions and experimental results. Nevertheless, several experiments have failed to achieve either agreement with the prevailing theory of consistency with each other - and improved experiments do not remove these discrepancies. The authors discuss two recent experiments at U.S.C. which indicate that there remain fundamental questions beyond experimental uncertainties. One of these is the stability of superflow in a complex texture in the A-phase. Experimental evidence indicates that superflow may actually be stabilized by the existence of a texture. The other is the long-standing discrepancy between static (SQUID) and dynamic (NMR) measurements of the magnetization discontinuity at the A-B transition. The authors recent experiments using a first principles measurement of [Delta]M support the continued existence of the discrepancy.