Critical supersaturation of−43He liquid mixtures: Decay of metastable states at ultralow temperatures

We report the results of the first systematic study of the phase separation from supersaturated ${}_{}{}^3{}_{}{}^{}\mathrm{-}_{}^4{}_{}{}^{}$He liquid mixtures of dilute phase in the temperature range from 130 mK down to 400 μK. We find that the degree of critical supersaturation becomes almost temperature independent below about 10 mK while it increases with temperature above about 10 mK.