  Indistinguishability of particles is a major factor destabilizing crystalline
order in Bose systems. We describe this effect in terms of damped
quasi-particle modes and in the dual language of Feynman paths, and illustrate
it by first-principle simulations of dipolar bosons and bulk condensed
helium-four. The first major implication is that, contrary to conventional
wisdom, zero-point motion alone cannot prevent helium-four crystallization at
low temperature, at saturated vapour pressure. Secondly, Bose statistics leads
to quantum jamming at finite temperature, dramatically enhancing the
metastability of superfluid glasses. Only studies of indistinguishable
particles can reliably address these issues.
