title: Site-selective mott transition in a quasi-one-dimensional vanadate V6O13.
abstract: The microscopic mechanism of the metal-insulator transition is studied by orbital-resolved ^{51}V NMR spectroscopy in a prototype of the quasi-one-dimensional system V6O13. We uncover that the transition involves a site-selective d orbital order lifting twofold orbital degeneracy in one of the two VO6 chains. The other chain leaves paramagnetic moments on the singly occupied d(xy) orbital across the transition. The two chains respectively stabilize an orbital-assisted spin-Peierls state and an antiferromagnetic long-range order in the ground state. The site-selective Mott transition may be a source of the anomalous metal and the Mott-Peierls duality.
authors.affiliation: Department of Physics, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Shimizu
authors.affiliation: Department of Physics, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Aoyama
authors.affiliation: Department of Physics, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan.
authors.forename: Takaaki
authors.initials: T
authors.lastname: Jinno
authors.affiliation: Department of Physics, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Itoh
authors.affiliation: Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Ueda