25 citations · 100 across the 16 of their papers we have counts for
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Stabilizing Itinerant Electrons in a Corner-Sharing Kagomé Oxide Nd4Os3ZnO14
Ryutaro Okuma, Yuita Fujisawa, Chia-Hsiu Hsu +8
Kagome oxides provide a fertile platform for exploring exotic electronic states arising from geometrical frustration and characteristic band topology. Here, we report the synthesis…
Molecular-Orbital Degeneracy Lifting and Suppression of a Flat-Band Metal in a Tetrahedral Cluster System NbSeI
Keita Kojima, Youichi Yamakawa, Ryutaro Okuma +7
The lifting of degenerate electronic states has been extensively studied in transition metal compounds, where diverse quantum phenomena arise from the degrees of freedom of d elect…
Odd-parity multipole order in the spin-orbit coupled metallic pyrochlore PbReO
Yuki Nakayama, Daigorou Hirai, Hajime Sagayama +6
The pyrochlore oxide Pb2Re2O7-δ (PRO) is a candidate spin-orbit-coupled metal (SOCM) that exhibits a structural phase transition with inversion symmetry breaking. In this study, we…
Metastable ordered states induced by low temperature annealing of δ-Ag2/3V2O5
T. Kubo, K. Kojima, N. Katayama +5
In δ-Ag2/3V2O5 with charge degrees of freedom in V, it is known that the charge ordering state and physical properties of V that appear at low temperatures depend strongly on the o…
Zigzag chain order of LiVSe developing away from the vanadium trimer phase transition boundary
K. Kojima, N. Katayama, K. Sugimoto +3
The phenomenon of self-assembly of constituent elements to form molecules at low temperatures appears ubiquitously in transition metal compounds with orbital degrees of freedom. Re…
Linear Trimer Formation by Three-Center-Four-Electron Bonding in RuP
Daigorou Hirai, Keita Kojima, Naoyuki Katayama +3
In molecules like hydrogen, most chemical bonds are formed by sharing two electrons from each atom in the bonding molecular orbital (two-center-two-electron (2c2e) bonding). There…
Observation of local atomic displacements intrinsic to the double zigzag chain structure of 1T-MTe2 (M = V, Nb, Ta)
N. Katayama, Y. Matsuda, K. Kojima +7
We describe the existence of local distortion discovered in the synchrotron x-ray single-crystal structure analysis of layered ditelluride 1T-MTe2 (M = V, Nb, Ta). In 1T-TaTe2, the…
Charge-ordered state satisfying the Anderson condition in LiRh2O4 arising from local dimer order
Manabu Shiomi, Keita Kojima, Naoyuki Katayama +8
We report on the charge-ordered structure of LiRh2O4 arising below the metal-insulator transition at 170 K. Structural studies using synchrotron X-rays have revealed that the charg…
Slow dynamics of disordered zigzag chain molecules in layered LiVS2 under electron irradiation
Naoyuki Katayama, Keita Kojima, Tomoki Yamaguchi +8
Electronic instabilities in transition metal compounds often spontaneously form orbital molecules, which consist of orbital-coupled metal ions at low temperature. Recent local stru…
Vanadium trimers randomly aligned along the c-axis direction in layered LiVO2
K. Kojima, N. Katayama, S. Tamura +2
Herein, we discuss the identification of vanadium trimers in layered LiVO2 and its sulfide analog of LiVS2 with two-dimensional triangular lattices. Our comprehensive structural st…