Université de Fribourg

Inhibition of the photoinduced structural phase transition in the excitonic insulator ${\mathrm{Ta}}_{2}{\mathrm{NiSe}}_{5}$

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

In: Physical Review B, 2018, vol. 97, no. 11, p. 115154

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...