Scaling Results for Superfluid 3He in 98% Open Aerogel

Abstract

We present experimental observations of the suppressed superfluid transition temperature, Tca, superfluid fraction, rs/r and Leggett frequency of 3He-B in aerogel, WBa. We determine Tca from mass decoupling and the vanishing of the frequency shift away from the Larmor frequency in our different samples and different laboratories. We find that the suppressed transition temperature for 3He in aerogel occurs at a sample dependent, but approximately pressure independent, length, X =x0(P)/p1−Tca/Tc, where Tc and x0(P), are the transition temperature and the pressure dependent zero temperature coherence length for bulk 3He. Tca also occurs at a pressure independent value of the Leggett frequency of bulk 3He-B. Further, we find that when the superfluid fraction and square of the Leggett frequency are plotted against Tca −T (and not (Tca −T)/Tca), the results of each measurement nearly collapse on to a pressure independent but sample dependent plot, with no further scaling. When plotted on a log-log scale, both measurements exhibit power laws in the range 1.33-1.45. PACS numbers: 67.57.Bc, 67.57.Lm, 67.57.Pq