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Kohn Anomalies and Electron-Phonon Interaction in Graphite

S. Piscanec·M. Lazzeri·F. Mauri·A. C. Ferrari·J. Robertson
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Abstract

We demonstrate that graphite phonon dispersions have two Kohn anomalies at the Gamma-E_2g and K-A'1 modes. The anomalies are revealed by two sharp kinks. By an exact analytic derivation, we show that the slope of these kinks is proportional to the square of the electron-phonon coupling (EPC). Thus, we can directly measure the EPC from the experimental dispersions. The Gamma-E_2g and K-A'1 EPCs are particularly large, whilst they are negligible for all the other modes at Gamma and K.

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S. Piscanec, M. Lazzeri, F. Mauri, A. C. Ferrari, J. Robertson. 2004-09-21. Kohn Anomalies and Electron-Phonon Interaction in Graphite. https://doi.org/10.1103/physrevlett.93.185503

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