AVS 49th International Symposium
    Nanometer Structures Wednesday Sessions
       Session NS-WeP

Paper NS-WeP3
Dispersion Relation of the Electromagnetic Waves in the Strong-coupling Superconductive Nano-disk

Wednesday, November 6, 2002, 11:00 am, Room Exhibit Hall B2

Session: Nanometer Structures B
Presenter: D.V. Reznik, Institute of Semiconductor Physics NAS of Ukraine
Authors: V.Z. Lozovski, Institute of Semiconductor Physics NAS of Ukraine
D.V. Reznik, Institute of Semiconductor Physics NAS of Ukraine
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The investigated system consists of the superconductor disk on the surface a dielectric substrat. We study the dispersion relations of the electromagnetc waves which can be excitated in the system. The dimensions of the disk is order of 100-1000 Å. We take into account the strong coupling of the superconductor in the framework of the enhanced u-v- transformations method which was developed in.@footnone 1@ The dispersion relation are determine by the pole part of the effective susceptibility. The susceptibility is calculated by solution of Lipman-Shwinger self-consistent equation. This equation is solved by exact summation of iteration procedure series proposed in.@footnote 2@ The initial receptivity was written in terms of u-v-coefficients. One takes into consideration strong-coupling. We take into account the despersion of the phonon energy and perturbation of the electron energy spectrum at Fermi level by electron-phonon interaction. The proposed approach allows us to calculate the effective nonlocal susceptibility for the both weak and strong coupling superconductors. As it is shown in@footnote 2@ the effective susceptibility can be rewritten as the tensor product of the initial susceptibility and inverse mass operator. Then the electromagnetic waves dispersion relations are determined by the roots of the real part of the determinant of the effective susceptibility inverse matrix. The dispersion curves depend on the electromagnetic properties of the substrate and disk material, the strength of the coupling in superconductor and the geometry of the system (thickness and radius of the disk). Moreover, dispersion depends on coordinate in which electromagnetic field is investigated. @FootnoteText@ @footnote 1@ B.I. Khudik, V.Z. Lozovski, A.B. Nazarenko, Phys. Stat. Sol.(b) 148, 297-303 (1988). @footnote 2@ V.Z. Lozovski, Physica E, 9, 642-651 (2001).