Excitonic insulator state in Ta2NiSe5 probed by photoemission spectroscopy

Y. Wakisaka, T. Sudayama, K. Takubo, T. Mizokawa, M. Arita, H. Namatame, M. Taniguchi, N. Katayama, M. Nohara, H. Takagi

    Research output: Contribution to journalArticlepeer-review

    177 Citations (Scopus)


    We report on a photoemission study of Ta2NiSe5 that has a quasi-one-dimensional structure and an insulating ground state. Ni 2p core-level spectra show that the Ni 3d subshell is partially occupied and the Ni 3d states are heavily hybridized with the Se 4p states. In angle-resolved photoemission spectra, the valence-band top is found to be extremely flat, indicating that the ground state can be viewed as an excitonic insulator state between the Ni 3d-Se 4p hole and the Ta 5d electron. We argue that the high atomic polarizability of Se plays an important role to stabilize the excitonic state.

    Original languageEnglish
    Article number026402
    JournalPhysical Review Letters
    Issue number2
    Publication statusPublished - Aug 6 2009

    ASJC Scopus subject areas

    • Physics and Astronomy(all)


    Dive into the research topics of 'Excitonic insulator state in Ta2NiSe5 probed by photoemission spectroscopy'. Together they form a unique fingerprint.

    Cite this