English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
Add to Basket
  Local TagsRelease HistoryDetailsSummary

Released
Journal Article

Photo-excited dynamics in the excitonic insulator Ta2NiSe5

MPS-Authors
/persons/resource/persons280580

Takagi,  H.
Department Quantum Materials (Hidenori Takagi), Max Planck Institute for Solid State Research, Max Planck Society;

/persons/resource/persons280111

Kaiser,  S.
Department Solid State Spectroscopy (Bernhard Keimer), Max Planck Institute for Solid State Research, Max Planck Society;
Former Research Groups, Max Planck Institute for Solid State Research, Max Planck Society;

External Resource
No external resources are shared
Fulltext (restricted access)
There are currently no full texts shared for your IP range.
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
There is no public supplementary material available
Citation

Werdehausen, D., Takayama, T., Albrecht, G., Lu, Y., Takagi, H., & Kaiser, S. (2018). Photo-excited dynamics in the excitonic insulator Ta2NiSe5. Journal of Physics: Condensed Matter, 30(30): 305602.


Cite as: https://hdl.handle.net/21.11116/0000-000E-D448-2
Abstract
The excitonic insulator is an intriguing correlated electron phase formed of condensed excitons. A promising candidate is the small band gap semiconductor Ta2NiSe5. Here we investigate the quasiparticle and coherent phonon dynamics in Ta2NiSe5 in a time resolved pump probe experiment. Using the models originally developed by Kabanov el al for superconductors (Kabanov et al 1999 Phys. Rev. B 59 1497), we show that the material's intrinsic gap can be described as almost temperature independent for temperatures up to about 250 K to 275 K. This behavior supports the existence of the excitonic insulator state in Ta2NiSe5. The onset of an additional temperature dependent component to the gap above these temperatures suggests that the material is located in the BEC-BCS crossover regime. Furthermore, we show that this state is very stable against strong photoexcitation, which reveals that the free charge carriers are unable to effectively screen the attractive Coulomb interaction between electrons and holes, likely due to the quasi 1D structure of Ta2NiSe5.