SOFT EXCITATION MODES OF QUANTUM BOSE FLUIDS IN THE LIQUID-SOLID PHASE-TRANSITION

We search for signatures of the liquid-solid phase transition in a gro up of strongly correlated quantum Bose fluids. We identify the non-sph erically symmetric excitation mode which becomes soft at the critical density as the driving mechanism of the phase transition. The symmetry of the soft mode indicates the point-group symmetry of the arising so lid phase. We place special emphasis on, examining the effect of the s hort- and long-range features of the interaction on the crystal struct ure. Where possible, comparison with experiments and Monte Carlo resul ts is made and a good agreement in the critical densities is found. Th e analysis reveals new features in the phase diagram of the charged Bo se fluid.