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arXiv · 0707.0349

Metallic Graphene Nanodisks

Motohiko Ezawa
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Abstract

We explore the electronic properties of finite-length graphene nanoribbons as well as graphene nanodisks with various sizes and shapes in quest of metallic ones. For this purpose it is sufficient to search zero-energy states. We find that there exist no zero-energy states in finite-length zigzag nanoribbons though all infinite-length zigzag nanoribbons have zero-energy states. The occurrence of zero-energy states is surprisingly rare. Among typical nanodisks, only trigonal zigzag nanodisks have degenerate zero-energy states and show metallic ferromagnetism, where the degeneracy can be controlled arbitrarily by designing the size. A remarkable property is that the relaxation time is quite large in spite of its small size in trigonal zigzag nanodisks.

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Motohiko Ezawa. 2007-07-03. Metallic Graphene Nanodisks. https://doi.org/10.1103/physrevb.76.245415

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