“…In particular, with a sufficiently strong cross-repulsion between two components, phase separation occurs [11,12]. It lies in the base of many related configurations and phenomena of high interest, such as domain walls and surface tension between segregated condensates [4,13], the dynamics of bubbles [14], the quantum counterparts of classical hydrodynamic instabilities (Kelvin-Helmholtz [15,16], Rayleigh-Taylor [17][18][19], Plateau-Rayleigh [20], the parametric instability of capillary waves at the interface [21]), complex textures in rotating binary condensates [22][23][24], vortices with filled cores [3,[25][26][27][28][29][30], three-dimensional topological structures [31][32][33][34][35], etc.…”