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Microscopic theory of the coupling of intrinsic Josephson oscillations and phonons

Ch. Preis·Ch. Helm·K. Schmalzl·Ch. Walter·J. Keller
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Abstract

A microscopic theory for the coupling of intrinsic Josephson oscillations and dispersive phonon branches in layered superconductors is developed. Thereby the effect of phonons on the electronic c-axis transport enters through an effective longitudinal dielectric function. This coupling provides an explanation of recently observed subgap resonances in the $I_{dc}$-$V_{dc}$- curve of anisotropic cuprate superconductors forming a stack of short Josephson junctions. Due to the finite dispersion these resonances can appear at van-Hove-singularities of both optical and acoustical phonon branches, explaining low-voltage structures in the I-V-characteristic, which are not understood in phonon models without dispersion. In long junctions the dispersion of collective electron-phonon modes parallel to the layers is investigated.

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Ch. Preis, Ch. Helm, K. Schmalzl, Ch. Walter, J. Keller. 2000-01-12. Microscopic theory of the coupling of intrinsic Josephson oscillations and phonons. https://doi.org/10.1016/s0921-4534(00)01329-0

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