It is shown that high-frequency electrostatic surface waves (SW) could be propagated at right angles to an external magnetic field on the boundary between metal and gaseous plasma due to a finite pressure electron gas in quantum plasma by using the quantum hydrodynamic QHD equations. The dispersion relation for those surface waves in uniform electron plasma is derived under strong external magnetic field. We have shown that the electrostatic surface waves exist also in the frequency for the ranges where electromagnetic SW is impossible. The surface plasma modes are nu- merically evaluated for the specific case of gold metallic plasma at room temperature. It has been found that dispersion relation of surface modes depends significantly on these quantum effects (Bohm potential and statistical) and should be into account in the case of magnetized or unmagnetized plasma. |