Tunneling spectroscopy in Bi2Sr2CaCu2O8+x single-crystal break junctions: reproducible determination of the Eliashberg function and role of the breakdown of Migdal's theorem

doi:10.1016/S0921-4534(97)00842-3

Physica C: Superconductivity

Volumes 282–287, Part 3, August 1997, Pages 1473-1474

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Abstract

We discuss the reproducible results in the determination of the electron-phonon spectral function α²(ω)F(ω) we recently obtained from tunneling data in Bi₂Sr₂CaCu₂O_8+x single-crystal break junctions with T_c = 93 K. The results give evidence for a strong electron-phonon interaction (λ = 2.94 ± 0.34) possibly restricted to selected phonon modes. The role of the breakdown of Migdal's theorem is also discussed by calculating the bare value of λ and, by direct solution of the Eliashberg equations, the corresponding new values of T_c and Δ(0).

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Tunneling spectroscopy in Bi2Sr2CaCu2O8+x single-crystal break junctions: reproducible determination of the Eliashberg function and role of the breakdown of Migdal's theorem

Abstract

Physica C

Physica C

Phys. Rev. B

Tunneling spectroscopy in Bi₂Sr₂CaCu₂O_8+x single-crystal break junctions: reproducible determination of the Eliashberg function and role of the breakdown of Migdal's theorem