@article {Zhang20113615,
	title = {Discriminative generation and hydrogen modulation of the Dirac-Fermi polarons at graphene edges and atomic vacancies},
	journal = {Carbon},
	volume = {49},
	number = {11},
	year = {2011},
	note = {n/a},
	pages = {3615 - 3621},
	abstract = {<p>Using a combination of the bond order{\textendash}length{\textendash}strength correlation theory, the spin-polarized tight binding method, the first-principles calculations, and the atomistic photoelectron distillation experiments, we investigated the mechanisms of edge-selective generation and hydrogenated modulation of Dirac-Fermi polarons (DFPs) surrounding the atomic vacancies at a graphite surface and at the edges of graphene nanoribbons (GNR). We found that: (i) the \{DFPs\} with a high-spin density at a zigzag-GNR edge and at an atomic vacancy result from the isolation and polarization of the dangling σ-bond electrons of √3d (d is the C{\textendash}C bond length) distance along the edge by the locally and densely entrapped bonding electrons; (ii) along an armchair-GNR edge and a reconstructed-zigzag-GNR edge, however, the formation of quasi-triple-bond between the nearest edge atoms of d distance prevents the \{DFPs\} from generation; and (iii) hydrogenation reduces the spin density substantially and turns the asymmetric dumb-bell-like density into the spherical-like pz density. A further C 1s photoelectron spectroscopic purification has confirmed that the generation of the \{DFPs\} is associated with two extra peaks of energy states located at the bottom and the top edge of the C 1s band.</p>
},
	issn = {0008-6223},
	doi = {10.1016/j.carbon.2011.04.064},
	url = {http://www.sciencedirect.com/science/article/pii/S0008622311003393},
	author = {Xi Zhang and Yanguang Nie and Weitao Zheng and Jer-Lai Kuo and Chang Q. Sun}
}
