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O. Herranen

Publications and source records attributed to O. Herranen.

2 recordsLinked to original sources

Measurement of optical second-harmonic generation from an individual single-walled carbon nanotube

We show that optical second-harmonic generation (SHG) can be observed from individual single-walled carbon nanotubes (SWCNTs) and, furthermore, allows imaging of individual tubes. Detailed analysis of our results suggests that the structural noncentrosymmetry, as required for SHG, arises from the non-zero chiral angle of the SWCNT. SHG thus has potential as a fast, non-destructive, and simple method for imaging of individual nanomolecules and for probing their chiral properties. Even more, it opens the possibility to optically determine the handedness of individual SWCNTs.

cond-mat.mes-hall

Linear current fluctuations in the power-law region of metallic carbon nanotubes

We study low frequency noise in a non-Ohmic region of metallic single walled and multiwalled carbon nanotubes. The generalized relative noise appear to be independent of applied bias in the power-law regime of the tubes and in agreement with theoretical predictions. Beyond the power law regime the suppression of conductance due to scattering with optical phonons is accompanied by a reduction of relative noise by an order of magnitude. Mobility fluctuations in the tubes due to optical phonon scattering cause the unexpected reduction in the relative noise magnitude which is modeled using a modified mobility fluctuation picture. The findings have important implications for metallic nanotubes being used as interconnects in nanoelectronic devices.

cond-mat.mes-hall