Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Scientists at PKU and UC Berkeley illustrate an atlas of carbon nanotube optical transitions

Figure 1. Scheme of determining chiral index and optical resonances of the same individual carbon nanotubes through combined electron diffraction and Rayleigh scattering techniques
Figure 1. Scheme of determining chiral index and optical resonances of the same individual carbon nanotubes through combined electron diffraction and Rayleigh scattering techniques

Abstract:
Led by Professor Wang Enge at Peking University (PKU) and Professor Wang Feng at the University of California, Berkeley, a joint research team recently reported their major progress on an atlas of carbon nanotube optical transitions, which was published in Nature Nanotechnology 7, 325 (2012).

Scientists at PKU and UC Berkeley illustrate an atlas of carbon nanotube optical transitions

Beijing, China | Posted on May 17th, 2012

Periodic table is one of the most important discoveries ever in science because it presents a systematic structure-property relation for each atom. A similar relation is equally important for nanostructures as the material properties of nanostructures depend sensitively on their structures. Single-walled carbon nanotubes (SWNTs), a model one-dimensional (1D) nanomaterial system, constitute a rich family of structures with distinctly different electrical and optical properties. The diversity of nanotube physical properties, together with their perfect structural integrity, makes SWNTs model systems to probe 1D physics and to promise materials for nanoscale electronics and photonics. However, a long-standing goal in nanotube research is how to establish the structure-property relation for hundreds of different SWNTs species with high accuracy.

The researchers illustrated the first comprehensive and accurate map between the structure and optical transitions in SWNTs through independent determination of chiral indices and optical transitions in over 200 individual nanotubes (Fig. 1). This map, effectively an "atlas" for SWNT optical transitions, has an uncertainty less than 20meV. It provides a valuable reference for nanotube spectroscopic identification, electronic and photonic applications. Once they know the optical resonances of a single-walled nanotube, they can identify its chiral index without any ambiguity, and vice versa.

In addition, this atlas opens the door for systematic understanding of fascinating 1D many-body effects in SWNTs of different types and diameters. By systematically investigating the electron-electron interaction induced optical resonance shifts in different nanotubes, they discovered surprisingly that the Fermi velocity renormalization is the same in metallic and semiconducting SWNTs, but increases monotonically with nanotube diameter towards the two-dimensional graphene limit (Fig. 2). This unusual behavior reveals an intriguing perfect cancellation of long-range electron-electron interaction effects and a diameter dependent short-range electron-electron interaction effects.

This study demonstrates the importance of a systematic approach in characterizing the property-structure relation in nanostructures. The atlas provides the prerequisite reference for the future energy-related applications. The revealed distinct behavior of long-range and short-range electron-electron interactions can be of general importance for differing low-dimensional materials.

The work was partly supported by the National Natural Science Foundation of China (NSFC) and the Ministry of Science and Technology (MOST).

Edited by: Zhang Jiang

Source: International Center for Quantum Materials

####

About Peking University
Peking University is a comprehensive and national key university. The campus, known as "Yan Yuan"(the garden of Yan), is situated at Haidian District in the western suburb of Beijing, with a total area of 2,743,532 square metres (or 274 hectares). It stands near to the Yuanmingyuan Garden and the Summer Palace.



Peking University is proud of its outstanding faculty, including 53 members of the Chinese Academy of Sciences (CAS), 7 members of the Chinese Academy of Engineering (CAE), and 14 members of the Third World Academy of Sciences (TWAS).



The university has effectively combined research on important scientific subjects with the training of personnel with a high level of specialized knowledge and professional skill as demanded by the country's socialist modernization. It strives not only for improvements in teaching and research work, but also for the promotion of interaction and mutual promotion among various disciplines.



Thus Peking University has become a center for teaching and research and a university of a new type, embracing diverse branches of learning such as basic and applied sciences, social sciences and the humanities, and sciences of medicine, management, and education. Its aim is to rank among the world's best universities in the future.

For more information, please click here

Copyright © Peking University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Imaging electric charge propagating along microbial nanowires October 20th, 2014

Design of micro and nanoparticles to improve treatments for Alzheimers and Parkinsons: At the Faculty of Pharmacy of the UPV/EHU-University of the Basque Country encapsulation techniques are being developed to deliver correctly and effectively certain drugs October 20th, 2014

Physicists build reversible laser tractor beam October 20th, 2014

Removal of Limitations of Composites at Superheat Temperatures October 20th, 2014

Nanotubes/Buckyballs

Imaging electric charge propagating along microbial nanowires October 20th, 2014

Beyond LEDs: Brighter, new energy-saving flat panel lights based on carbon nanotubes - Planar light source using a phosphor screen with highly crystalline single-walled carbon nanotubes (SWCNTs) as field emitters demonstrates its potential for energy-efficient lighting device October 14th, 2014

NTU develops ultra-fast charging batteries that last 20 years October 14th, 2014

Fast, cheap nanomanufacturing: Arrays of tiny conical tips that eject ionized materials could fabricate nanoscale devices cheaply October 4th, 2014

Discoveries

Imaging electric charge propagating along microbial nanowires October 20th, 2014

Design of micro and nanoparticles to improve treatments for Alzheimers and Parkinsons: At the Faculty of Pharmacy of the UPV/EHU-University of the Basque Country encapsulation techniques are being developed to deliver correctly and effectively certain drugs October 20th, 2014

Physicists build reversible laser tractor beam October 20th, 2014

Removal of Limitations of Composites at Superheat Temperatures October 20th, 2014

Announcements

Imaging electric charge propagating along microbial nanowires October 20th, 2014

Design of micro and nanoparticles to improve treatments for Alzheimers and Parkinsons: At the Faculty of Pharmacy of the UPV/EHU-University of the Basque Country encapsulation techniques are being developed to deliver correctly and effectively certain drugs October 20th, 2014

Physicists build reversible laser tractor beam October 20th, 2014

Removal of Limitations of Composites at Superheat Temperatures October 20th, 2014

Photonics/Optics/Lasers

Physicists build reversible laser tractor beam October 20th, 2014

Magnetic mirrors enable new technologies by reflecting light in uncanny ways October 16th, 2014

New VDMA Association "Electronics, Micro and Nano Technologies" founded: Inaugural Meeting in Frankfurt/Main, Germany October 15th, 2014

Nanodevices for clinical diagnostic with potential for the international market: The development is based on optical principles and provides precision and allows saving vital time for the patient October 15th, 2014

Research partnerships

Crystallizing the DNA nanotechnology dream: Scientists have designed the first large DNA crystals with precisely prescribed depths and complex 3D features, which could create revolutionary nanodevices October 20th, 2014

IRLYNX and CEA-Leti to Streamline New CMOS-based Infrared Sensing Modules Dedicated to Human-activities Characterization October 15th, 2014

Scientists Map Key Moment in Assembly of DNA-Splitting Molecular Machine: Crucial steps and surprising structures revealed in the genesis of the enzyme that divides the DNA double helix during cell replication October 15th, 2014

Unique catalysts for hydrogen fuel cells synthesized in ordinary kitchen microwave oven October 14th, 2014

NanoNews-Digest
The latest news from around the world, FREE





  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More














ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE