An instantaneous blue shift of exciton absorption due to the optical Stark effect was observed in isolated semiconducting single-walled carbon nanotubes (SWNTs) by using a femtosecond (fs) pump-probe spectroscopy. From the analysis of time profiles of transient absorption changes, the photoinduced shift and the dipole moment of the exciton transition were evaluated as ∼1.1 meV for the pump fluence of 34 μJ/cm2 and ∼6 eÅ, respectively. Such a large dipole moment as well as ultrafast recovery of real carrier excitations suggests high potential of SWNTs for an ultrafast optical-switching material.
|ジャーナル||Japanese Journal of Applied Physics, Part 2: Letters|
|出版ステータス||Published - 2006 5月 19|
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