Inhibition of the photoinduced structural phase transition in the excitonic insulator Ta2NiSe5

  title={Inhibition of the photoinduced structural phase transition in the excitonic insulator Ta2NiSe5},
  author={Selene Mor and M. Herzog and Johannes Noack and Naoyuki Katayama and Minoru Nohara and Hidenori Takagi and Annette Trunschke and Takashi Mizokawa and Claude Monney and Julia Stahler},
  journal={Physical Review B},
Femtosecond time-resolved mid-infrared reflectivity is used to investigate the electron and phonon dynamics occurring at the direct band gap of the excitonic insulator Ta$_2$NiSe$_5$ below the critical temperature of its structural phase transition. We find that the phonon dynamics show a strong coupling to the excitation of free carriers at the \Gamma\ point of the Brillouin zone. The optical response saturates at a critical excitation fluence $F_C = 0.30~\pm~0.08$~mJ/cm$^2$ due to optical… 

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