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Evidence for ubiquitous strong electron-phonon coupling in high-temperature superconductors

A. Lanzara·P. V. Bogdanov·X. J. Zhou·S. A. Kellar·D. L. Feng·E. D. Lu·T. Yoshida·H. Eisaki·A. Fujimori·K. Kishio·J. -I. Shimoyama·T. Noda·S. Uchida·Z. Hussain·Z. -X. Shen
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Abstract

Coupling between electrons and phonons (lattice vibrations) drives the formation of the electron pairs responsible for conventional superconductivity. The lack of direct evidence for electron-phonon coupling in the electron dynamics of the high transition temperature superconductors has driven an intensive search for an alternative mechanism. A coupling of an electron with a phonon would result in an abrupt change of its velocity and scattering rate near the phonon energy. Here we use angle resolved photoemission spectroscopy to probe electron dynamics -velocity and scattering rate- for three different families of copper oxide superconductors. We see in all of these materials an abrupt change of electron velocity at 50-80meV, which we cannot explain by any known process other than to invoke coupling with the phonons associated with the movement of the oxygen atoms. This suggests that electron-phonon coupling strongly influences the electron dynamics in the high-temperature superconductors, and must therefore be included in any microscopic theory of superconductivity.

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A. Lanzara, P. V. Bogdanov, X. J. Zhou, S. A. Kellar, D. L. Feng, E. D. Lu, T. Yoshida, H. Eisaki, A. Fujimori, K. Kishio, J. -I. Shimoyama, T. Noda, S. Uchida, Z. Hussain, Z. -X. Shen. 2001-07-10. Evidence for ubiquitous strong electron-phonon coupling in high-temperature superconductors. https://doi.org/10.1038/35087518

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