Abstract
We demonstrate that graphite phonon dispersions have two Kohn anomalies at the and 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 and EPCs are particularly large, while they are negligible for all the other modes at and .
- Received 23 April 2004
DOI:https://doi.org/10.1103/PhysRevLett.93.185503
©2004 American Physical Society