Electronic structure and magnetic properties of graphitic ribbons
Electronic structure and magnetic properties of graphitic ribbons
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DOI：
10.1103/physrevb.75.064418
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发表时间：
2007-02-01
影响因子：
3.7
通讯作者：
Harrison, N. M.
中科院分区：
文献类型：
--
作者：
Pisani, L.;Chan, J. A.;Harrison, N. M.
第一原理计算用于确定具有锯齿形边缘的石墨烯带的电子结构对于边缘态的磁极化而言是不稳定的。人们发现边缘态之间的磁相互作用范围非常长，并且与带的电子结构密切相关。使用电子交换和相关性的各种处理来检查该结果对电子-电子相互作用的细节的敏感性，并且发现定性特征与近似的细节无关。明确考虑了其他稳定机制的可能性，例如电荷排序和 Peierls 畸变，并且发现这些机制对于合理宽度的带是不利的。这些结果对于使用适当调制的磁场控制石墨纳米带中的自旋相关电导具有直接影响。
First-principles calculations are used to establish that the electronic structure of graphene ribbons with zigzag edges is unstable with respect to magnetic polarization of the edge states. The magnetic interaction between edge states is found to be remarkably long ranged and intimately connected to the electronic structure of the ribbon. Various treatments of electronic exchange and correlation are used to examine the sensitivity of this result to details of the electron-electron interactions, and the qualitative features are found to be independent of the details of the approximation. The possibility of other stablization mechanisms, such as charge ordering and a Peierls distortion, are explicitly considered and found to be unfavorable for ribbons of reasonable width. These results have direct implications for the control of the spin-dependent conductance in graphitic nanoribbons using suitably modulated magnetic fields.