Nonequilibrium carrier dynamics in FeSe0.8Te0.2

We report on the nonequilibrium dynamics of photoinduced collective excitations in FeSe0.8Te0.2 superconducting (SC) thin film. The obtained transient reflectance traces show three distinct regions attributed to different dynamical processes. First two processes are observed within a sub-picosecond scale and are associated with photoexcitation of quasi-particles (QP). The first process is attributed to QPs accumulation and is sensitive to structural anisotropy. We use nematicity measurements to determine its time constant. The electron-phonon coupling constant of lambda = 0.2 was derived and is consistent with previous studies for similar materials. Strong acoustic phonons generation was observed on a longer timescale.

Automated summary

We investigated the nonequilibrium dynamics of photoinduced collective excitations in FeSe0.8Te0.2 superconducting thin film. The transient reflectance traces showed three distinct regions corresponding to different dynamical processes. The first two processes occurred within a sub-picosecond timescale and were associated with the photoexcitation of quasi-particles (QP). The first process was attributed to QPs accumulation and was found to be sensitive to structural anisotropy. The longer timescale revealed the generation of strong acoustic phonons.