@article{9464b88180854804ad228245a3170106,
title = "Spin excitations in the quasi-two-dimensional charge-ordered insulator α-(BEDT-TTF)2 I3 probed via C 13 NMR",
abstract = "The spin excitations from the nonmagnetic charge-ordered insulating state of α-(BEDT-TTF)2I3 at ambient pressure have been investigated by probing the static and low-frequency dynamic spin susceptibilities via site-selective nuclear magnetic resonance at C13 sites. The site-dependent values of the shift and the spin-lattice relaxation rate 1/T1 below the charge-ordering transition temperature (TCO≈135K) demonstrate a spin density imbalance in the unit cell, in accord with the charge-density ratio reported earlier. The shift and 1/T1 show activated temperature dependence with a static (shift) gap ΔS≈47-52meV and a dynamic (1/T1) gap ΔR≈40meV. The sizes of the gaps are well described in terms of a localized spin model, where spin-1/2 antiferromagnetic dimer chains are weakly coupled with each other.",
author = "Kyohei Ishikawa and Michihiro Hirata and Dong Liu and Kazuya Miyagawa and Masafumi Tamura and Kazushi Kanoda",
note = "Funding Information: The authors thank R. Kondo and H. Sawa for informing us about the structural data and the local electronic density distribution on triiodine anions before publication. We also thank N. Tajima, A. Kawamoto, and T. Takahashi for informing us about the detailed experimental results and Y. Suzumura, A. Kobayashi, H. Fukuyama, Y. Tanaka, and M. Ogata for fruitful discussions. This paper is supported by Ministry of Education, Culture, Sports, Science and Technology (MEXT) Grant-in-Aids for Scientific Research on Innovative Area (New Frontier of Materials Science Opened by Molecular Degrees of Freedom; No. 20110002), Japan Society for the Promotion of Science (JSPS) Postdoctoral Fellowships for Research Abroad (Grant No. 66, 2013), and JSPS Grant-in-Aids for Scientific Research (S) (No. 25220709). Publisher Copyright: {\textcopyright}2016 American Physical Society.",
year = "2016",
month = aug,
day = "31",
doi = "10.1103/PhysRevB.94.085154",
language = "English",
volume = "94",
journal = "Physical Review B",
issn = "2469-9950",
publisher = "American Physical Society",
number = "8",
}