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Exchange Enhancement of the Electron-Phonon Pair Interaction

D. Manske·C. T. Rieck·D. Fay
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Abstract

The critical temperature of high-$T_c$ superconductors is determined, at least in part, by the electron-phonon coupling. We include the effect of an exchange interaction between the electrons and calculate the renormalization of the bare phonon frequencies and the electron-phonon verticies in a random phase approximation and obtain a strongly enhanced attractive phonon-induced electron-electron interaction. Using Fast Fourier Transform techniques, the weak-coupling selfconsistency equation for the order parameter is solved in the 2D first Brillouin zone for the Emery tight-binding band with different band fillings. The enhancement of $T_c$ arises primarily from the softening of the phonon frequencies rather than the vertex renormalization.

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D. Manske, C. T. Rieck, D. Fay. 1994-07-01. Exchange Enhancement of the Electron-Phonon Pair Interaction. https://doi.org/10.1016/0921-4534(94)92285-3

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