Condensed Matter Physics Seminar

2 p.m., Thursday, February 1, 2007
Room 1201, Physics Building

Optical Spectroscopy of Semiconducting and Metallic Nanostructures

Feng Wang

(UC Berkeley)

Abstract: Many new physical phenomena emerge when materials are structured on the nanometer length scale. These systems offer excellent opportunities for the study of physics in lower dimensions. Optical spectroscopy, with its high sensitivity and spectral specificity, provides a versatile probe for their investigation. These opportunities are exemplified by the study of single-walled carbon nanotubes (SWNTs), a family of more than 100 highly one-dimensional (1D) structures. To identify and characterize SWNTs, we have developed a new technique capable of measuring the optical spectra of individual nanotubes. The method permits detailed analysis of the optical transitions as a function of the nanotube structure. We have also explored the physical nature of these optical transitions. We found that many-body interactions play a dominant role in both semiconducting and metallic SWNTs. These effects arise from the greatly enhanced strength of Coulomb interactions that are characteristic of such 1D systems.

Host: Fuhrer
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