Effectively unpaired electrons in bipartite lattices within the generalized tight-binding approximation: application to graphene nanoflakes

• Veröffentlicht in: Functional Materials
• Datum: 2014
• 1. Verfasser: Luzanov, A.V.
• Format: Artikel
• Sprache: Englisch
• Veröffentlicht: НТК «Інститут монокристалів» НАН України 2014
• Schlagworte: Modeling and simulation
• Online Zugang: https://nasplib.isofts.kiev.ua/handle/123456789/120487
• Назва журналу: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Zitieren: Effectively unpaired electrons in bipartite lattices within the generalized tight-binding approximation: application to graphene nanoflakes / A.V. Luzanov // Functional Materials. — 2014. — Т. 21, № 4. — С. 437-447. — Бібліогр.: 61 назв. — англ.

A semiempirical technique is proposed for bipartite structures (lattice-like systems with two interpenetrating sublattices). For such systems, the corresponding one-electron tight-binding model can be easily modified to include electron correlation effects, although in a rough manner. It allows one to describe the so-called effectively unpaired electrons (EUE) in giant many-electron systems by using even uncomplicated hardware. The average EUE occupancy is interpreted as a counterpart of the order parameter reflecting a hidden antiferromagnetic structure of the strongly correlated system. We illustrate the developed method by analyzing EUE for several model problems (nanoflakes and nanoribbons) mimicking the graphene-based materials.