Ultrafast dynamics and coherent order parameter oscillations under photo-excitation in the excitonic insulator Ta2NiSe5
Abstract
The excitonic insulator (EI) is an intriguing phase of condensed excitons undergoing a Bose-Einstein-Condensation (BEC)-type transition. A prominent candidate has been identified in Ta2NiSe5. Ultrafast spectroscopy allows tracing the coherent response of the EI condensate directly in the time domain. Probing the collective electronic response we can identify fingerprints for the Higgs-amplitude equivalent mode of the condensate. In addition we find a peculiar coupling of the EI phase to a low frequency phonon mode. We will discuss the transient response on multiple energies scales ranging from the exciton dynamics to the coherent THz response of the gap.
Citation
Werdehausen , D , Agustsson , S Y , Kim , M , Shabestari , P , Huang , E , Pokharel , A , Larkin , T , Boris , A , Takayama , T , Lu , Y , Rost , A W , Chu , H , Yaresko , A , Höppner , M , Schulz , A , Manske , D , Keimer , B , Takagi , H & Kaiser , S 2018 , Ultrafast dynamics and coherent order parameter oscillations under photo-excitation in the excitonic insulator Ta 2 NiSe 5 . in M K Rafailov (ed.) , Ultrafast Bandgap Photonics III . , 1063803 , Proceedings of SPIE , vol. 10638 , SPIE , pp. 1-7 , Ultrafast Bandgap Photonics III 2018 , Orlando , Florida , United States , 16/04/18 . https://doi.org/10.1117/12.2304795 conference
Publication
Ultrafast Bandgap Photonics III
ISSN
0277-786XType
Conference item
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