Ultrafast carrier dynamics caused by photoexcitation in quasi-one-dimensional two-leg ladder cuprate Sr4Ca 10Cu24O41 was investigated by the femtosecond reflection spectroscopy. After the photoexcitation along the leg direction, the transient reflectivity changes (ΔR/R) in the mid-infrared region showed instant decrease within 150 fs. The suppressed ΔR/R increased so rapidly on the picosecond time scale that the reflectivity value finally became larger than that in the initial state. Such a successive response in ΔR/R, which was also observed in other photon energy regions, is discussed in terms of ultrafast variation of the Drude weight in the ladder system by the photoirradiation.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)