Investigation of femtosecond electronic dephasing in CdSe nanocrystals using quantum-beat-suppressed photon echoes

R. W. Schoenlein; D. M. Mittleman; J. J. Shiang; A. P. Alivisatos; C. V. Shank

doi:10.1103/PhysRevLett.70.1014

Investigation of femtosecond electronic dephasing in CdSe nanocrystals using quantum-beat-suppressed photon echoes

R. W. Schoenlein, D. M. Mittleman, J. J. Shiang, A. P. Alivisatos, and C. V. Shank

Phys. Rev. Lett. 70, 1014 – Published 15 February 1993

Abstract

We report the first direct measurements of femtosecond electronic dephasing in CdSe nanocrystals using three-pulse photon echoes and a novel mode-suppression technique. We are able to separate the dynamics of the coherently excited LO phonons from the underlying electron-hole dephasing by suppressing the quantum beats. The homogeneous linewidth of these materials at 15 K results from electronic dephasing in ∼85 fs, approximately half of which is due to acoustic phonon modes. Contributions from acoustic phonons dominate the homogeneous linewidth at room temperature.

Received 19 August 1992

DOI:https://doi.org/10.1103/PhysRevLett.70.1014

Authors & Affiliations

R. W. Schoenlein, D. M. Mittleman, J. J. Shiang, A. P. Alivisatos, and C. V. Shank

Lawrence Berkeley Laboratory, 1 Cyclotron Road, MS 70-193A, Berkeley, California 94720
Department of Physics, University of California, Berkeley, California 94720
Department of Chemistry, University of California, Berkeley, California 94720