Fermi-Liquid Droplets in Liquid-Solid Solutions of the Helium Isotopes

Abstract

For temperatures below phase separation of 1000 ppm $^{3}\mathrm{He}$ in solid $^{4}\mathrm{He}$, we measure a heat capacity $\ensuremath{\gamma}T$ for a pressure between melting of pure $^{3}\mathrm{He}$ and $^{4}\mathrm{He}$. Together with the confined sample geometry, this results in liquid $^{3}\mathrm{He}$ droplets ($\ensuremath{\phi}\ensuremath{\sim}{10}^{3}$ \AA{}) either dilute or pure depending on the phase diagram topology which is discussed theoretically. In the case of a pure $^{3}\mathrm{He}$ droplet, an anomalously high effective mass $\frac{{m}^{*}}{m}=10$ is found, which could be explained by paramagnon effects enhanced by the confined geometry.