標題: Effects of a Modulated Electric Field on the Optical Absorption Spectra in a Single-Layer Graphene
作者: Chiu, Yu-Huang
Ho, Jon-Hsu
Ho, Yen-Hung
Chuu, Der-San
Lin, Ming-Fa
電子物理學系
Department of Electrophysics
關鍵字: Graphene;Modulated Electric Field;Optical
公開日期: 1-Nov-2009
摘要: The optical absorption spectra of a graphene monolayer in the presence of a modulated electric field are investigated by the gradient approximation with tight-binding model. Such a field could strongly affect the low-energy electronic and optical properties. The low-energy bands exhibit two kinds of band-edge states (mu and nu), which lead to many prominent asymmetric peaks in the density of states (DOS). The finite DOS at omega = 0 implies that a single layer graphene in the presence of modulated electric fields would become a semimetallic one. The low-frequency optical absorption spectra display rich peaks and they vanish at omega = 0. Such absorption peaks mainly result from the two kinds of band-edge states and could be divided into two groups. However, they could not be ascribed to an obvious selection rule. It is worth noting that the optical absorption spectra could show anisotropic features in different modulated directions. The predicted results could be verified by the experimental measurements.
URI: http://dx.doi.org/10.1166/jnn.2009.1340
http://hdl.handle.net/11536/6451
ISSN: 1533-4880
DOI: 10.1166/jnn.2009.1340
期刊: JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
Volume: 9
Issue: 11
起始頁: 6579
結束頁: 6586
Appears in Collections:Articles