Events Calendar

 
Seminar

"Circular dichroism and plasmonic absorption of light in carbon nanotubes" by Prof. Riichiro Saito, Tohoku University, Sendai, Japan

Thursday, 18 July 2019, 13:30-15:00
KIT, Campus Nord
Institute of Nanotechnology
Bldg. 640 Seminar Room 0-167
Hermann-von-Helmholtz-Platz 1
76344 Eggenstein-Leopoldshafen

Talk given by

Prof. Dr. Riichiro Saito

Department of Physics

Tohoku University

Sendai, Japan

 

Abstract:

In the case of chiral carbon nanotubes that do not have a mirror symmetry around the nanotube axis, circular dichroism of light occurs. Circular dichroism is defined by the difference of the optical absorption for left-handed and right-handed circularly polarized light. We calculate circular dichroism of carbon nanotube as a function of wavelength of light and as a function of chirality and diameter of nanotubes, which is compared with experimental results. In the experiment, since the direction of nanotubes is random in solution, we expected that the averaged circular dichroism for the direction may appear. However, the experimental results are similar to the calculated one for the specific geometry in which the nanotube axis is perpendicular to the propagation direction of circularly polarized light. Thus we expect that the depolarization effect of a nanotube is important in the circularly dichroism, for which we will show our recent work.

When a carbon nanotube is doped, the single-particle excitation is suppressed and new optical absorption spectra appear in the experiment. This situation can be explained by so-called plasmonic optical absorption which is evaluated by calculating dielectric function. Further we will discuss the circularly dichroism for the plasmonic absorption of doped carbon nanotubes.

 

 

This event is part of the eventgroup INT Talks
Speaker
Prof. Riichiro Saito

Tohoku University, Sendai, Japan
Department of Physics
Organizer
Prof. Ralph Krupke
Institut für Nanotechnologie
KIT
Karlsruhe
Mail: ralph krupke does-not-exist.kit edu
https://www.int.kit.edu
Targetgroup
Interested / Everyone
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