The recently reported subgap structures observed in the current-voltage characteristic of intrinsic Josephson junctions in the high-T_c superconductors Tl_2Ba_2Ca_2Cu_3O_{10+\delta} and Bi_2Sr_2CaCu_2O_{8+\delta} are explained by the coupling between c-axis phonons and Josephson oscillations. A model is developed where c-axis lattice vibrations between adjacent superconducting multilayers are excited by the Josephson oscillations in a resistive junction. The voltages of the lowest structures correspond well to the frequencies of longitudinal c-axis phonons with large oscillator strength in the two materials, providing a new measurement technique for this quantity.
@article{arxiv.cond-mat/9701049,
title = {Coupling between phonons and intrinsic Josephson oscillations in cuprate superconductors},
author = {Ch. Helm and Ch. Preis and F. Forsthofer and J. Keller and K. Schlenga and R. Kleiner and P. Mueller},
journal= {arXiv preprint arXiv:cond-mat/9701049},
year = {2009}
}
Comments
4 pages, 3 figures, revtex, aps, epsf, psfig. submitted to Physical Review Letters, second version improved in detail