Surface and waveguide Josephson plasma waves in slabs of layered superconductors

Abstract

We discuss propagation of symmetric and antisymmetric Josephson plasma waves in a slab of layered superconductor clad between two identical dielectrics. We predict two branches of surface waves in the terahertz frequency range, one above and another below the Josephson plasma frequency. Apart from this, there exists a discrete set of waveguide modes with electromagnetic fields oscillating across the slab thickness and decaying exponentially away from the slab. We consider the excitation of the predicted waves by means of the attenuated-total-reflection method.It is shown that for specific set of the parameters of the structure the excitation of the waveguide modes is accompanied by total suppression of specular reflection.

Enhanced transmission of terahertz radiation through a periodically modulated slab of layered superconductor

“…The equation D = 0 with f = 0, i.e. with F = 0 in equations (13), defines the spectrum of symmetric and antisymmetric waveguide eigenmodes [14]. The weak modulation of the plasma frequency (3) gives rise to a shift of the dispersion curves and to additional damping due to the leakage of the eigenmode energy via a diffracted wave.…”

“…Therefore, the diffracted waves serve as carriers of electromagnetic energy, similarly to the helicons, dopplerons and cyclotron waves described in [7][8][9]. Thus, the diffraction in metals can result in the resonant excitation of the symmetric or antisymmetric evanescent surface waves, whereas the diffraction in the layered superconductors provides more effective resonant excitation of waveguide modes (WGMs) (see [13,14]), which do not decay inside the slab but oscillate across the layers.…”

Resonant coupling of Rayleigh waves through a narrow fluid channel causing extraordinary low acoustic transmission

“…15 Similar effect of suppression of specular reflection was predicted in layered superconductors due to resonant excitation of Josephson plasma waves. 16 Suppression of transmission and also reflection is due to abnormal absorption of electromagnetic energy at the resonance.…”

Infrared nanospectroscopy and imaging of collective superfluid excitations in anisotropic superconductors

“…The collective mode spectrum of the cuprates has been derived previously. 14,25,26 Here, we provide a brief overview, starting with uniaxial materials in general. 27 Collective electromagnetic modes in a material correspond to poles of the reflectivity coefficient r P , which depends on both material constants and geometry.…”