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

Selene Mor, Marc Herzog, Johannes Noack, Naoyuki Katayama, Minoru Nohara, Hide Takagi, Annette Trunschke, Takashi Mizokawa, Claude Monney, Julia Stähler

Research output: Contribution to journalArticlepeer-review

31 Citations (Scopus)


Femtosecond time-resolved midinfrared reflectivity is used to investigate the electron and phonon dynamics occurring at the direct band gap of the excitonic insulator Ta2NiSe5 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 Γ point of the Brillouin zone. The optical response saturates at a critical excitation fluence FC=0.30±0.08 mJ/cm2 due to optical absorption saturation. This limits the optical excitation density in Ta2NiSe5 so that the system cannot be pumped sufficiently strongly to undergo the structural change to the high-temperature phase. We thereby demonstrate that Ta2NiSe5 exhibits a blocking mechanism when pumped in the near-infrared regime, preventing a nonthermal structural phase transition.

Original languageEnglish
Article number115154
JournalPhysical Review B
Issue number11
Publication statusPublished - 2018 Mar 26

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics


Dive into the research topics of 'Inhibition of the photoinduced structural phase transition in the excitonic insulator Ta2NiSe5'. Together they form a unique fingerprint.

Cite this