  The theory of hole superconductivity proposes that superconductivity
originates in the fundamental electron-hole asymmetry of condensed matter and
that it is an 'undressing' transition. Here we propose that a natural
consequence of this theory is that superconductors behave as giant atoms. The
model predicts that the charge distribution in superconductors is
inhomogeneous, with higher concentration of negative charge near the surface.
Some of this negative charge will spill out, giving rise to a negative electron
layer right outside the surface of the superconductor, which should be
experimentally detectable. Also superconductors should have a tendency to
easily lose negative charge and become positively charged. Macroscopic spin
currents are predicted to exist in superconducting bodies, giving rise to
electric fields near the surface of multiply connected superconductors that
should be experimentally detectable.
