Spectroscopy of Many-Body Effects in Carbon Nanotubes
Abstract
The goal of this research project was to explore the fundamental properties of degenerate one-dimensional (1-D) electrons in single-walled carbon nanotubes (SWNTs) using dynamical methods to probe and understand electronic correlations and many-body phenomena. We studied two aspects of 1-D electron correlations in SWNTs: Fermi-edge singularities (FES) and conduction electron spin resonance (ESR). For the FES project, three major strides were taken: first, a detailed design of the carbon nanotube field effect transistor structure was made, and a step-by-step procedure was followed for fabrication; second, micro-photoluminescence was performed on individual SWNTs in the presence of external electric fields; and third, we made the first direct observation of "dark" excitons in individual SWNTs through low-temperature micro-magneto-photoluminescence spectroscopy. The ESR project has broken new ground on our current understanding of spin resonance in SWNTs. Last year, we discovered that oxygen plays a key role in the electron spin dynamics in nanotubes. Comparing temperature dependent ESR data taken on the same nanotube film in the water-free condition and in the water-free and oxygen-free condition, we were able to perform a detailed lineshape analysis. Several new observations resulted, including an increase in the spin susceptibility when oxygen is removed, Curie-law behavior for the water-free spin susceptibility, linewidth motional narrowing, and saturation of the absorption curve at high microwave powers. In addition, work has begun on producing sample configurations for the single-tube ESR experiment.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 15, 2010
- Accession Number
- ADA533146
Entities
People
- Junichiro Kono
Organizations
- Rice University