[institut] seminar Emmanuele Cappelluti

[Rados Gajic]

Postovane Koleginice i Kolege,
sledeceg petka 4. novembra ce Dr. Emmanuele Cappelluti
odrzati sledeci seminar u biblioteci sa pocetkom
u 12 casova.

Mnogo pozdrava, Rados.

------------------------------------------------------------------------
Phonon anomalies in optical conductivity of
graphene-based materials

Emmanuele Cappelluti

Instituto de Ciencia de Materiales de Madrid (ICMM),
CSIC, Madrid, Spain

Abstract
Single and multilayer graphenes are among the most promising
systems for the development of carbon-based devices in electronics.
The detection and analysis of the spectral properties
of optical phonons in single- and multi-layer graphene
provides a powerful tool not only for investigating the role of the
underlying electron-phonon interaction,
but also for a careful characterization of the systems.
While large amount of work along this direction has initially focused
on Raman spectroscopy, phonon anomalies have been recently
detected also in the infrared optical conductivity of bilayer graphene,
revealing a remarkable tunable dependence of the intensity and of the
Fano lineshape asymmetry on the external gate voltage.
In this talk I will present a simple theoretical framework which
permits to understand at the same time the phonon intensity
and the Fano lineshape asymmetry.
A complete phase diagram of the optical phonon response is also
presented, as a function of both the charge density and the bandgap,
showing a switching mechanism,
between the dominance of the Eu and Eg mode.
controlled by the external gate voltage.
The case of multilayer graphene and graphite is also discussed.
------------------------------------------------------------------------