Mesoscopic fluctuations of the dipole moment and the electric polarizability

We consider mesoscopic fluctuations of the dipole moment and the electric polarizability of a disordered thin film in the diffusive regime. It is shown, that the requirement of a fixed particle number is crucial for obtaining finite fluctuations at low temperatures. For systems with sufficient disorder and a long screening length a spontaneous dipole moment should be observable with an atomic force microscope.Dedicated to Prof. H. Wagner on the occasion of his 60th birthday