Plasma Waves in Anisotropic Superconducting Films Below and Above the Plasma Frequency

Abstract

We consider wave propagation inside an anisotropic superconducting film sandwiched between two semi-infinite non-conducting bounding dieletric media such that along the c-axis, perpendicular to the surfaces, there is a plasma frequency ${\omega }_p$ below the superconducting gap. Propagation is assumed to be parallel to the surfaces in the dielectric medium, where amplitudes decay exponentially.Below ${\omega }_p$, the amplitude also evanesces inside the film, and we retrieve the experimentally measured lower dispersion relation branch, $\omega \propto \sqrt{\beta }$, and the recently proposed higher frequency branch, $\omega \propto 1/\sqrt{\beta }$.Above ${\omega }_p$, propagation is of the guided wave type, i.e., a dispersive plane wave confined inside the film that reflects into the dielectric interfaces,and the modes are approximately described by $\omega \approx {\omega }_p\sqrt{1+(\beta /{\beta }_0{)}^2}$, where ${\beta }_0$ is discussed here.

26 pages,4 figures.Submitted

Cited by in corpus (1)

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