Phonons and superconductivity in YBa2Cu3O7

G. L. Zhao; J. Callaway

doi:10.1103/PhysRevB.50.9511

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Phonons and superconductivity in YBa2Cu3O7

G. L. Zhao, J. Callaway

DOI 10.1103/PhysRevB.50.9511 · Physical Review B

T1

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Abstract

We report the results of a calculation of the electron-phonon interaction in YBa2Cu3O7 based on the nonorthogonal tight-binding approach to lattice dynamics. A self-consistent local-density electronic-structure calculation was combined with a shell-model description of the phonon spectrum. The resulting interaction matrix was used to calculate the superconducting transition temperature from a solution of the Eliashberg equations in which the full k dependence was retained. The transition temperature was found to be about 90 K, quite close to experiment. The oxygen isotope effect was investigated. We also calculated the k-dependent gap function at T=0. The gap shows significant variation between different sheets of the Fermi surface as well as dependence on k on the individual sheets, but is nodeless. The quantity 2ΔkBTc varies from 6.0 to 2.5 on the Fermi surface.

Source-reported materials — not catalogue approval

Formula	Reported Tc (K)	Pressure (GPa)	Type
YBa2Cu3O7 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	90	Pressure not reported	unknown