The closed-orbit and the photoabsorption spectra of the Rydberg hydrogen atom between two parallel metallic surfaces

Using the closed orbit theory, we study the classical motion and calculate thephotoabsorption spectra of Rydberg hydrogen atom between two parallel metallic surfaces. The results show that the metallic surfaces have a significant effecton the photoabsorption process. When the distances between the hydrogen atomand the two metallic surfaces are close to a critical value d_c, the numberof the closed orbits is the greatest. When the distance larger or smallerthan d_c, the number of the closed orbits decreases and the absorptionspectra are shown to exhibit a damping oscillation. This work is aninteresting new application of closed-orbit theory and is of potentialexperimental interest.