Electrically-induced polarization selection rules of a graphene quantum dot. (May 2018)

• Record Type: Journal Article
• Authors: Dong, Qing-Rui; Li, Yan; Jia, Chen; Wang, Fu-Li; Zhang, Ya-Ting; Liu, Chun-Xiang
• Is Part Of: Solid state communications. Volume 273(2018)
• Page Start: 55
• Page End: 59
• Publication Date: 2018-05
• Subjects: A. Graphene quantum dots -- D. Selection rules; Solid state chemistry -- Periodicals; Solid state physics -- Periodicals; Chimie de l'état solide -- Périodiques; Physique de l'état solide -- Périodiques; 530.41
• DOI: 10.1016/j.ssc.2018.02.009
• Languages: English
• ISSNs: 0038-1098

Abstract

Abstract: We study theoretically the single-electron triangular zigzag graphene quantum dot in uniform in-plane electric fields. The absorption spectra of the dot are calculated by the tight-binding method. The energy spectra and the distribution of wave functions are also presented to analyse the absorption spectra. The orthogonal zero-energy eigenstates are arranged along to the direction of the external field. The remarkable result is that all intraband transitions and some interband transitions are forbidden when the absorbed light is polarized along the direction of the electric field. With x -direction electric field, all intraband absorption is y polarized due to the electric-field-direction-polarization selection rule. Moreover, with y -direction electric field, all absorption is either x or y polarized due to the parity selection rule as well as to the electric-field-direction-polarization selection rule. Our calculation shows that the formation of the absorption spectra is co-decided by the polarization selection rules and the overlap between the eigenstates of the transition. Highlights: All intraband transitions are forbidden when the absorbed light is polarized along the direction of the electric field. All intraband absorption is y polarized with x-direction electric field. All absorption is either x or y polarized with y-direction electric field. The spectra is co-decided by the polarization selection rules and the overlap between the eigenstates of the transition.