Two-DimensionalHe3inHe4Films

Abstract

Measurements and analysis of heat capacity for ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ in ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ films at temperatures below 350 mK are reported. The data show that ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ is less bound to the free surface of the ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ film than to the bulk ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ surface, and that it has a larger effective mass. Both of these parameters depend on ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ surface coverage. The ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ dissolved within the film behaves as a two-dimensional system for sufficiently thin ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ films.