Double photo-ionization of he near a polarizable surfaces

We calculate the differential cross section of the direct double photoionization of He physisorbed on apolarizable surface. By including the influence of the surface potential in the correlated two-electron final-statewave function, we show that the differential cross section carries detailed information on the electroniccorrelations at the surface. In particular, photoemission along opposite directions, which is prohibited in thefree space, is allowed if the surface potential is long ranged.