Paper Describes Approach to the Critical Point

The collaboration between Dr. Erik Luijten (University of Mainz, Germany) and Horst Meyer (Fundamental Physics investigator at Duke University) has led to a paper which has been submitted for publication. The title is "Crossover behavior in 3He and Xe near their liquid--vapor critical point" by Luijten and Meyer. In this paper the authors present a detailed discussion of the crossover from mean-field to Ising critical behavior upon approach of the critical point, both for 3He and Xe. By combining different sets of experimental data, they are able to cover an unusually large temperature range on either side of the critical temperature, Tc. Below Tc, an accurate comparison could be made with a recent numerical calculation by Luijten for the crossover of the coexistence curve. For the regime above Tc, the analysis of the compressibility and comparison with predictions demonstrates that the crossover regime in 3He is unexpectedly widened in respect to predictions and to that for Xe. This is believed to be caused by an interplay between quantum fluctuations and critical fluctuations.