Excitons in carbon nanotubes revisited: Dependence on diameter, Aharonov-Bohm flux, and strain
Excitons in carbon nanotubes revisited: Dependence on diameter, Aharonov-Bohm flux, and strain
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DOI：
10.1143/jpsj.73.3351
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发表时间：
2004-12-01
影响因子：
1.7
通讯作者：
Ando, T
中科院分区：
文献类型：
--
作者：
Ando, T
在 k(.)P 方案中存在磁通量和应变的情况下计算半导体碳纳米管的光谱。激子吸收能量在按倒数直径缩放后显示出对直径的额外对数依赖性，这来自于带隙的增强。激子结合能几乎保持独立于额外的依赖性。对于较宽的有效相互作用参数范围，第一能带和第二能带的吸收能之比接近于1.8。通过库仑相互作用，小磁通量中的阿哈罗诺夫-玻姆分裂增强（5-10%），并且由于应变引起的位移也增强（10-20%）。
Optical spectra are calculated in semiconducting carbon nanotubes in the presence of magnetic flux and strain within a k(.)P scheme. The exciton absorption energies show an extra logarithmic dependence on the diameter after being scaled by the inverse diameter, coming from that of the enhancement of the band gaps. The exciton binding energy remains almost independent of the extra dependence. The ratio of the absorption energies of the first and second bands is similar to1.8 for the wide range of the effective interaction parameter. By the Coulomb interaction, the Aharonov-Bohm splitting in small magnetic flux is enhanced (5-10%) and the shift due to strain is also enhanced (10-20%).