Ultrafast carrier relaxation dynamics in single-layer cuprates

This is the authors' abstract. We don't add key points for this paper.

Using a femtosecond pump-probe optical technique, we measured the time-resolv ed change in reflectivity of three single-layer cuprate samples, including Bi 2 Sr 2 − x La x CuO 6 + z , La 2 CuO 4 + y and La 2 − x Sr x CuO 4 grown on SrTiO 3 . We analyze the data in terms of a nonthermal electron relaxation model, and obtain quantitative agreement between the model and the data. The initial electron-electron thermalization process is much longer in the superconducting samples as opposed to the overdoped nonsuperconducting sample, suggesting a bottleneck in electron thermalization process due to the presence of the superconducting gap.