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arXiv 1104.2688cond-mat.mes-hall
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石墨烯纳米带的光学选择规则

Optical selection rules of graphene nanoribbons

H. C. Chung, M. H. Lee, C. P. Chang, M. F. Lin

摘要:

基于紧束缚模型,对一维石墨烯纳米带的光学选择规则进行了解析研究。通过分析速度矩阵元素和波函数的特征,可以从理论上解释这种选择规则,这种选择规则取决于纳米粒子的边缘结构,即扶手椅形或锯齿形边缘。扶手椅型纳米带的选择规则为ΔJ=0,光学跃迁发生在从导带到同指数的价电子带之间。这样的选择规则起源于两个子晶格之间的关系和传导和价带之间的关系。另一方面,锯齿形纳米带表现出选择规则|ΔJ| =奇数,这是由随着子带索引增加而交替改变的对称性特性引起的。应用选择定则得到了跃迁能的有效理论预测。此外,通过光学测量,带边态的能量变得可以通过实验获得。

英文摘要:

Optical selection rules for one-dimensional graphene nanoribbons are analytically studied and clarified based on the tight-binding model. A theoretical explanation, through analyzing the velocity matrix elements and the features of wavefunctions, can account for the selection rules, which depend on the edge structure of nanoribbon, namely armchair or zigzag edges. The selection rule of armchair nanoribbons is ΔJ=0, and the optical transitions occur from the conduction to valence subbands of the same index. Such a selection rule originates in the relationships between two sublattices and between conduction and valence subbands. On the other hand, zigzag nanoribbons exhibit the selection rule |ΔJ|=odd, which results from the alternatively changing symmetry property as the subband index increases. An efficiently theoretical prediction on transition energies is obtained with the application of selection rules. Furthermore, the energies of band edge states become experimentally attainable via optical measurements.

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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