# The electron-phonon origin of graphene $\pi^{*}$-band kink demonstrated by isotope substitution.

Priante F., Bisti F., Fedorov A.V., Donarelli M., Fantasia M., Petaccia L., Frank O., Kalbac M., Profeta G., Gruneis A., Ottaviano L.

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II - Fisica della materia
GSSI Ex ISEF - Aula C - Venerdì 27 h 09:00 - 12:00
The sudden change (known as kink) in the $\pi^{*}$-band dispersion near the Fermi level of Li-decorated graphene is investigated by isotope substitution. A reduced kink binding energy of 8 meV emerges from the comparison between the band structures of normal (${}^{13}C$) graphene and the heavy (${}^{13}C$) one. Such shift is in excellent agreement with the expected softening of the phonon energy distribution in the heavy graphene. This provides the experimental proof of the electron-phonon coupling being the origin of this band structure sudden change at 170 meV.