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Title: Dirac charge dynamics in graphene by infrared spectroscopy

Journal Article · · Nature Physics
OSTI ID:936742

A remarkable manifestation of the quantum character of electrons in matter is offered by graphene, a single atomic layer of graphite. Unlike conventional solids where electrons are described with the Schrödinger equation, electronic excitations in graphene are governed by the Dirac hamiltonian. Some of the intriguing electronic properties of graphene, such as massless Dirac quasiparticles with linear energy-momentum dispersion, have been confirmed by recent observations. Here, we report an infrared spectromicroscopy study of charge dynamics in graphene integrated in gated devices. Our measurements verify the expected characteristics of graphene and, owing to the previously unattainable accuracy of infrared experiments, also uncover significant departures of the quasiparticle dynamics from predictions made for Dirac fermions in idealized, free-standing graphene. Several observations reported here indicate the relevance of many-body interactions to the electromagnetic response of graphene.

Research Organization:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Organization:
Advanced Light Source Division
DOE Contract Number:
DE-AC02-05CH11231
OSTI ID:
936742
Report Number(s):
LBNL-878E; TRN: US0805691
Journal Information:
Nature Physics, Vol. 4, Issue 7; Related Information: Journal Publication Date: July 2008
Country of Publication:
United States
Language:
English