A theory of electromagnetic surface-wave propagation on a plane superconductor–vacuum interface is presented. On the basis of a nonlocal description taking into account the finite size of the pair-bound state, the transverse and longitudinal parts of the conductivity response tensor are analyzed. Special emphasis is given to a study of the quasi-particle scattering and the two-quasi-particle emission and absorption processes in the near-local regime, i.e., the regime where nonlocal effects are incorporated in lowest order. Within the framework of the well-known semiclassical infinite-barrier model, the hydrodynamic model, extended to include nonlocal effects in the divergence-free part of the response, is used to establish a simple analytical expression for the dispersion relation of surface waves on a Cooper-paired superconductor. Attention is paid to the frequency dispersion of the waves near the superconducting gap.
© 1990 Optical Society of America
Original Manuscript: September 11, 1989
Manuscript Accepted: April 27, 1990
Published: November 1, 1990
Ole Keller, "Electromagnetic surface waves on a Cooper-paired superconductor," J. Opt. Soc. Am. B 7, 2229-2235 (1990)