Effects of disorder on bosonic superfluids

In this work we showed and review a modern approach to treat disorder in bosonic superfluids, within the framework of path-integral approach to quantum field theory. The methods we present are focused on the evaluation of physical quantities of interest, like the condensate depletion and normal-fluid particle density, using correlators evaluated in harmonic approximation. We treated different kinds of disorder and presented an original extension of the theory to the case of particles interacting with a finite-range potential, instead of the contact interaction. We also showed how this formalism can be applied to the problem of flux lines in type-II sueprconductors.