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Code: MOF	Time Slot/Poster Number: 5:30 - 5:50 pm	Session: Carbon based materials (nanotubes, graphene, carbon nanostructures)
On-Chip Rayleigh Imaging and Spectroscopy of Carbon Nanotubes
Jiwoong Park
Cornell University, Ithaca, NY

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Summary
We report a novel on-chip Rayleigh imaging technique using wide-field laser illumination to measure optical scattering from individual SWNTs on solid substrate with high spatial and spectral resolution. This method in conjunction with calibrated AFM measurements accurately measures resonance energies and diameters for large numbers of SWNTs in parallel. Applying this technique for fast mapping of key SWNT parameters, including electronic-types and chiral indices for individual SWNTs, position and frequency of chirality-changing events, and intertube interactions in both bundled and distant SWNTs. Additionally, we measure uniform resonance optical conductivity near 8e^2/h from different SWNTs based on absolute Rayleigh cross sections.

Code: MOF	Time Slot/Poster Number: 4:00 - 4:30 pm	Session: Carbon-Based Materials I
Raman Spectroscopy of Carbon Nanotubes
Federico Villalpando; Gene Dresselhaus; Mildred Dresselhaus
Massachusetts Institute of Technology, Cambridge, MA

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Summary
The study of graphene nanostructures has become a frontier area of condensed matter physics, and our focus is directed toward studying double wall carbon nanotubes (DWNTs) and their relation to graphene. Since carbon nanotubes can be either metallic or semiconducting, DWNTs come in four varieties S@S, M@S, S@M and M@M where S@M denotes a semiconducting tube inside a metallic tube. Studies on DWNTs are normally done on ensembles of tubes, so there is no easy way to assess the difference in behavior between the four varieties of DWNTS. For this reason our work focuses on Raman studies of individual DWNTs.

Code: MOF	Time Slot/Poster Number: 4:30 - 5:00 pm	Session: Carbon-Based Materials I
Resonance Raman Spectroscopy in Carbon Nanostructures
Marcos Pimenta
Federal University of Minas Gerais, Belo Horizonte/Mg, Brazil

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Summary
Resonance Raman spectroscopy is used to study the behavior of electrons and phonons in different types of carbon nanostructures. We will show that the determination of a resonant Raman map provides the structural (n,m) assignment of the nanotubes present in the sample and allows the study of linear carbon chains encapsulated inside a nanotube. We will also present experimental results of the dispersion of electrons and phonons in monolayer and bilayer graphene obtained from a resonant Raman study, and results in gated graphene devices where the position of the Fermi level can be changed by applying a gate voltage.

Code: MOF	Time Slot/Poster Number: 5:50 - 6:10 pm	Session: Carbon-Based Materials I
Resonant Raman Spectroscopy of Chirality-Enriched Semiconducting Single Walled Carbon Nanotubes
Juan G. Duque¹; Hang Chen²; Svetlana Kilina¹; Sergei Tretiak¹; Andy Shreve¹; Xiaomin Tu³; Ming Zheng³; Anna Swan²; Stephen K. Doorn¹
¹Los Alamos National Laboratory, Los Alamos, NM; ²Boston University, Boston, MA; ³National Institute of Standards and Technology, Gaithersburg, MD

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Summary
We present a Raman spectroscopic investigation of enriched semiconducting samples generated from ion chromatography of DNA-functionalized nanotubes. RBM profiles show very good separation of single chirality semiconducting fractions with very low cross-contamination from other nanotubes. G-band profiles allow testing of different models for the Raman scattering process and reveal new evidence for the importance of non-Condon effects in the Raman response. Investigations into the behavior of the highly dispersive G’ mode enabled us to map the band structure of the different isolated chiralities and to probe variable coupling in the vicinity of the E22 transition.