Shell structure in mixed 3He-4He droplets -: art. no. 023202

Due to the immiscibility of He-3 into He-4 at very low temperatures, mixed helium droplets consist of a core of He-4 atoms coated by a He-3 layer whose thickness depends on the number of atoms of each isotope. When these numbers are such that the centrifugal kinetic energy of the He-3 atoms is small and can be considered as a perturbation to the mean-field energy, a novel shell structure arises, with magic numbers different from these of pure He-3 droplets. If the outermost shell is not completely filled, the valence atoms align their spins up to the maximum value allowed by the Pauli principle.