  We review and discuss some recent developments on the unconventional
interaction between superconducting systems and the local gravitational field.
While it is known that gravitational perturbations (such as gravitational
waves) can affect supercondensates and supercurrents dynamics, here we want to
focus on the more subtle superfluid back-reaction acting on the surrounding
gravitational field, analysing some specific favourable situations. To this
end, we will consider suitable quantum macrosystems in a coherent state,
immersed in the static weak Earth's gravitational field, investigating possible
slight local alterations of the latter not explained in terms of classical
physics.
