83. Jahrestagung der DPG und DPG-Frühjahrstagung der Sektion Atome, Moleküle, Quantenoptik und Plasmen (SAMOP)
Sprache des Tagungstitel:
Recent experiments confirmed that fluctuations beyond the mean-field approximation can lead to self-bound liquid droplets of ultradilute binary Bose mixtures at very low temperatures. We study liquid Bose mixtures by using the variational hypernetted-chain Euler?Lagrange method, which accounts for correlations nonperturbatively. For the case of a uniform mixture, as it is found in the center of large droplets at saturation density, we study the conditions for stability against evaporation of one of the components (both chemical potentials need to be negative) and against liquid-gas phase separation, the spinodal instability. We discover that dilute Bose mixtures are stable only in a narrow range near an optimal ratio ? 1 /? 2 and in the vicinity of the total energy minimum. Despite the low density, deviations from a universal dependence on the s-wave scattering lengths are significant. We show how our results for uniform Bose mixtures can be extended to finite liquid droplets based on local density approximations.