Abstract
We report the observation of a coherent lattice oscillation in a pnictide superconductor. A coherent fully symmetric optical phonon was detected in ( and ) using time-resolved pump-probe reflectivity with 40 fs time resolution. The analysis of the phonon parameters for various excitation fluences reveals no evident difference below and above the critical temperature, suggesting that the mode is not involved in the superconducting phase transition.
- Received 31 July 2009
DOI:https://doi.org/10.1103/PhysRevB.80.172504
©2009 American Physical Society