arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 0711.0949cond-mat.mtrl-scicond-mat.mes-hall
收藏

局域横向电场作用下碳纳米管亚能隙态的形成

Formation of Subgap States in Carbon Nanotubes Due to a Local Transverse Electric Field

Jesse M. Kinder, E. J. Mele

摘要:

我们引入两个简单的模型来研究空间局域横向电场对半导体碳纳米管低能电子结构的影响。从碳纳米管低能态的狄拉克哈密顿量出发,利用散射理论证明了在任意弱场作用下,自由纳米管带隙内局域电子态的形成.我们研究了这些subgap状态的结合能作为静电势的范围和强度的函数。当电势范围保持不变而强度变化时,结合能表现出交叉行为:在电势超过阈值之前,结合能靠近自由纳米管带边,超过阈值后结合能迅速增加。当势强度保持不变,范围是变化的,我们发现共振行为:结合能通过一个最大值作为潜在的范围增加。大的电场局限于一个小区域的纳米管需要创建远离能带边缘的局域状态。

英文摘要:

We introduce two simple models to study the effect of a spatially localized transverse electric field on the low-energy electronic structure of semiconducting carbon nanotubes. Starting from the Dirac Hamiltonian for the low energy states of a carbon nanotube, we use scattering theory to show that an arbitrarily weak field leads to the formation of localized electronic states inside the free nanotube band gap. We study the binding energy of these subgap states as a function of the range and strength of the electrostatic potential. When the range of the potential is held constant and the strength is varied, the binding energy shows crossover behavior: the states lie close to the free nanotube band edge until the potential exceeds a threshold value, after which the binding energy increases rapidly. When the potential strength is held constant and the range is varied, we find resonant behavior: the binding energy passes through a maximum as the range of the potential is increased. Large electric fields confined to a small region of the nanotube are required to create localized states far from the band edge.

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。

↑