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arXiv 0712.2897cond-mat.mtrl-scicond-mat.mes-hall
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silicon carbide上外延石墨烯异常电子结构的成因

Origins of anomalous electronic structures of epitaxial graphene on silicon carbide

Seungchul Kim, Jisoon Ihm, Hyoung Joon Choi, Young-Woo Son

摘要:

在第一性原理计算的基础上,我们报道了在石墨烯和碳化硅表面之间出现了一种新的界面原子结构,破坏了石墨烯的狄拉克点,并在那里打开了一个相当大的能隙。在计算的原子结构,准周期$6\times 6$域模式出现了一个更大的相称的$6\sqrt{3}\times6\sqrt{3}R30^\circ$周期性的界面重建,解决了长期存在的实验争议的周期性的界面超结构。我们的理论能谱在石墨烯的Dirac点处显示出带隙和带隙中间态,这与最近观察到的异常角分辨光电子能谱非常一致。除了解决外延石墨烯无法解释的问题之外,我们的原子研究可能提供一种方法来设计衬底上石墨烯的能隙。

英文摘要:

On the basis of first-principles calculations, we report that a novel interfacial atomic structure occurs between graphene and the surface of silicon carbide, destroying the Dirac point of graphene and opening a substantial energy gap there. In the calculated atomic structures, a quasi-periodic $6\times 6$ domain pattern emerges out of a larger commensurate $6\sqrt{3}\times6\sqrt{3}R30^\circ$ periodic interfacial reconstruction, resolving a long standing experimental controversy on the periodicity of the interfacial superstructures. Our theoretical energy spectrum shows a gap and midgap states at the Dirac point of graphene, which are in excellent agreement with the recently-observed anomalous angle-resolved photoemission spectra. Beyond solving unexplained issues of epitaxial graphene, our atomistic study may provide a way to engineer the energy gaps of graphene on substrates.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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