Magnetic structure at zigzag edges of bilayer ribbons

• Type: Article in International Scientific Journal
• Date: 2008

Authors

Eduardo V Castro (Author) FCUP; Peres, NMR (Author) Other; Lopes M B L Dos Santos (Author) FCUP

Journal

Title: Journal of Optoelectronics and Advanced Materials

Vol. 10

Pages: 1716-1721

ISSN: 1454-4164

Publisher: National Institute of Research and Development for Optoelectronics

Indexing

ISI Web of Knowledge - 12 Citations

Scopus - 13 Citations

Scientific classification

FOS: Engineering and technology > Materials engineering

Other information

Authenticus ID: P-003-Y6Z

Abstract (EN): We study the edge magnetization of bilayer graphene ribbons with zigzag edges. The presence of flat edge-state bands at the Fermi energy of undoped bilayer, which gives rise to a strong peak in the density of states, makes bilayer ribbons magnetic at the edges even for very small on-site electronic repulsion. Working with the Hubbard model in the Hartree Fock approximation we show that the magnetic structure in bilayer ribbons with zigzag edges is ferromagnetic along the edge, involving sites of the two layers, and antiferromagnetic between opposite edges. It is also shown that this magnetic structure is a consequence of the nature of the edge states present in bilayer ribbons with zigzag edges. Analogously to the monolayer case, edge site magnetization as large as m approximate to 0.2 mu(B) (per lattice site) even at small on-site Hubbard repulsion U approximate to 0.3 eV is realized in nanometer wide ribbons.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 6