Separation between low-energy hole dynamics and spin dynamics in a frustrated magnet

Kou Takubo*, Yusuke Nambu, Satoru Nakatsuji, Yuki Wakisaka, Takaaki Sudayama, David Fournier, Giorgio Levy, Andrea Damascelli, Masashi Arita, Hirofumi Namatame, Masaki Taniguchi, Takashi Mizokawa

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

6 Citations (Scopus)


An angle-resolved photoemission spectroscopy (ARPES) study is reported on a Mott insulator NiGa2S4 in which Ni2+ (S=1) ions form a triangular lattice and the Ni spins do not order even in its ground state. The first ARPES study on the two-dimensional spin-disordered system shows that low-energy hole dynamics at high temperatures is characterized by wave vectors QE which are different from wave vectors QM dominating low-energy spin excitations at low temperatures. The unexpected difference between QE and QM is deeply related to charge fluctuation across the Mott gap in the frustrated lattice and is a key issue to understand the spin-disordered ground states in Mott insulators.

Original languageEnglish
Article number226404
JournalPhysical Review Letters
Issue number22
Publication statusPublished - 2010 Jun 3
Externally publishedYes

ASJC Scopus subject areas

  • Physics and Astronomy(all)


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