Logarithmic Singularities of Specific Heat and Related Properties of Liquid $^4He$ Near $\lambda-$Point

Abstract

The singularity of specific heat ($C_p$) and related properties (viz. thermal expansion coefficient, compressibility and pressure coefficient) of liquid $^4He$ at $\lambda-$point is studied and the accuracy of its logarithmic nature as concluded for the first time from a microscopic theory (cond-mat/0606571) of a system of interacting bosons is examined. A very good agreement between the results of this theory and experiments concludes that singularity is intrinsically logarithmic. However, as shown by other studies, weak effects arising from earth's gravity and small sample size round it off and $C_p$ assumes asymptotic nature near $T_{\lambda}$.