title: Structure-dependent Fano resonances in the infrared spectra of phonons in few-layer graphene.
abstract: The in-plane optical phonons around 200 meV in few-layer graphene are investigated utilizing infrared absorption spectroscopy. The phonon spectra exhibit unusual asymmetric features characteristic of Fano resonances, which depend critically on the layer thickness and stacking order of the sample. The phonon intensities in samples with rhombohedral (ABC) stacking are significantly higher than those with Bernal (AB) stacking. These observations reflect the strong coupling between phonons and interband electronic transitions in these systems and the distinctive variation in the joint density of electronic states in samples of differing thickness and stacking order.
authors.affiliation: Department of Physics, Columbia University, 538 West 120th Street, New York, New York 10027, USA.
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Li
authors.forename: Chun Hung
authors.initials: CH
authors.lastname: Lui
authors.forename: Emmanuele
authors.initials: E
authors.lastname: Cappelluti
authors.forename: Lara
authors.initials: L
authors.lastname: Benfatto
authors.forename: Kin Fai
authors.initials: KF
authors.lastname: Mak
authors.forename: G L
authors.initials: GL
authors.lastname: Carr
authors.forename: Jie
authors.initials: J
authors.lastname: Shan
authors.forename: Tony F
authors.initials: TF
authors.lastname: Heinz