物理化学学报 >> 2014, Vol. 30 >> Issue (3): 439-445.doi: 10.3866/PKU.WHXB201401141

理论与计算化学 上一篇    下一篇

石墨烯条带的电子结构与性质:电场及长度效应

孙进1, 梁万珍2   

  1. 1 安徽大学物理与材料科学学院, 合肥230039;
    2 厦门大学化学系, 福建厦门361005
  • 收稿日期:2013-10-09 修回日期:2014-01-14 发布日期:2014-02-27
  • 通讯作者: 孙进 E-mail:sunjin@ahu.edu.cn
  • 基金资助:

    国家自然科学基金(21103001)和高等学校博士学科点专项科研基金(20113401120004)资助项目

Effects of External Field and Nanoribbon Length on the Electronic Structure and Properties of Graphene Nanoribbons

SUN Jin1, LIANGWan-Zhen2   

  1. 1 School of Physics and Materials Science, Anhui University, Hefei 230039, P. R. China;
    2 Department of Chemistry, Xiamen University, Xiamen 361005, Fujian Province, P. R. China
  • Received:2013-10-09 Revised:2014-01-14 Published:2014-02-27
  • Contact: SUN Jin E-mail:sunjin@ahu.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21103001) and Research Fund for the Doctoral Programof Higher Education of China (20113401120004)

摘要:

在密度泛函理论(DFT)和含时密度泛函理论(TDDFT)的基础上对宽度上含有8个zigzag链的石墨烯条带(8-ZGNR)的基态和激发态的性质进行了理论研究, 着重考察了条带长度及电场的影响. B3LYP杂化泛函的计算结果显示: 在基态上, 8-ZGNR的最低能量态并不具有磁性, 随着长度的增加, 才会显示出反铁磁的性质. 静电场的加入使8-ZGNR显示出反铁磁性和半金属性.在激发态上, 诱导电子会随着外激光脉冲的变化而发生移动和变化, 但是相比而言, α自旋电子更容易被激发而产生较明显的诱导电子密度, 而β自旋电子则更容易脱离外激光场的控制而产生非绝热现象.

关键词: 石墨烯纳米条带, 含时密度泛函理论, 自旋密度, 诱导密度, 激光外场

Abstract:

We investigated the ground and excited state electronic properties of finite length zigzag graphene nanoribbons, using time-dependent density functional theory. The ground state of short graphene nanoribbons with eight Hatoms on their armchair edges (8-ZGNR) is diamagnetic, and antiferromagnetismcan be exhibited with increasing the length of nanoribbons. The antiferromagnetismand half-metallicity can also be shown when a static field is added. When a laser pulse is applied in the excited state, the induced electrons can move and change with the laser pulse. There exist some differences between α- and β-spin electrons. α-Spin electrons can be induced, and showinduced charge density more readily. β-Spin electrons can escape the external field control, and show non-adiabatic properties more readily.

Key words: Graphene nanoribbon, Time-dependent density functional theory, Spin density;, Induce density, Laser external field

MSC2000: 

  • O641