Scaling results for superfluid He-3 in 98% open aerogel

Parpia, J. M. and Fefferman, A. D. and Porto, J. V. and Dmitriev, V. V. and Levitin, L. V. and Zmeev, D. E. (2008) Scaling results for superfluid He-3 in 98% open aerogel. Journal of Low Temperature Physics, 150 (3-4). pp. 482-486. ISSN 0022-2291

Abstract

We present experimental observations of the suppressed superfluid transition temperature, T-ca, superfluid fraction, rho(s)/rho and Leggett frequency of He-3-B in aerogel, Omega(Ba). We determine T-ca 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 He-3 in aerogel occurs at a sample dependent, but approximately pressure independent, length, X = xi(0)(P)/root 1 - T-ca/T-c,T- where T-c and xi(0)(P), are the transition temperature and the pressure dependent zero temperature coherence length for bulk He-3. T-ca also occurs at a pressure independent value of the Leggett frequency of bulk He-3-B. Further, we find that when the superfluid fraction and square of the Leggett frequency are plotted against T-ca - T (and not (T-ca - T)/T-ca), 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.