Seminarium Optyczne

We numerically study the formation of self-bound quantum Bose-Fermi droplets at nonzero temperatures. We have previously shown that such droplets can exist at zero temperature. In this work the attractive atomic Bose-Fermi mixture is described in terms of quantum hydrodynamics, enriched by beyond mean-field corrections and thermal fluctuations, as well as by a simplified self-consistent Hartree-Fock model. Using the hydrodynamic description, we find low-temperature relatively long-lived droplets in a free space, provided that the attraction between bosons and fermions is strong enough. On the other hand, a simplified Hartree-Fock treatment supports the existence of Bose-Fermi droplets in equilibrium with the gas of thermal bosons and fermions, with the Bose-Einstein condensate itself being completely hidden inside a droplet. Both thermal and non-thermal droplets can be used to simulate astrophysical phenomena such as disruption of a white dwarf star by a black hole.