Effective Medium Theory of the Optical （有效介质理论的光学）.pdfVIP

VOLUME 78, NUMBER 22 P H Y S I C A L R E V I E W L E T T E R S 2 JUNE 1997 Effective Medium Theory of the Optical Properties of Aligned Carbon Nanotubes F. J. Garcı´a-Vidal,* J. M. Pitarke,† and J. B. Pendry Condensed Matter Theory Group, The Blackett Laboratory, Imperial College, London SW7 2BZ, United Kingdom (Received 16 January 1997; revised manuscript received 7 April 1997) We present an effective medium theory in order to analyze the reported optical properties of aligned carbon nanotube films [W. A. de Heer et al., Science 268, 845 (1995)]. This methodology is based on photonic band structure calculations and allows treatment of complex media consisting of particles that interact strongly. We also develop a simple Maxwell-Garnett type approach for studying this system. In comparing the results of both mean field theories, we demonstrate that the inclusion of the full electromagnetic coupling between the nanotubes, as our numerical scheme does, is necessary for a complete explanation of the experimental data. [S0031-9007(97)03308-5] PACS numbers: 78.66.Sq, 41.20.Jb, 61.46.+w, 73.20.Mf Since the discovery of tubular fullerenes in 1991 [1], Our idea is to apply a numerical methodology originally several experimental and theoretical studies of the unique constructed to study photonic materials and the propaga- properties of these materials have been carried out. De- tion of EM waves in complex media [8] to analyze the spite the short time since the first carbon nanotube was syn- optical properties of these carbon nanotube films where thesized, possible applications