The influence of a metallic sheet on an evanescent mode atomic mirror

A theory of evanescent mode atomic mirrors utilising a metallic sheet on a dielectric substrate is described. The emphasis here is on the role of the metallic sheet and on the evaluation of atomic trajectories using the field- dipole orientation picture. At low intensity, the atomic reflection process is controlled by two separate mechanisms both of which are modified by the presence of the metallic sheet and influenced by the use of the field-dipole orientation picture. The first mechanism involves the spontaneous force which accelerates the atom parallel to the sheet plane. The second mechanism involves the combined dipole plus van der Waals force which acts to repel the atom from the surface, decelerating its motion until it attains an instantaneous halt before changing direction away from the surface at an appr opriate turning point in the trajectory. Various quantitative features arising from varying the controllable parameters of the system, including screening effects as well as desirable enhancement effects, are pointed out and discussed.