Strong Correlation Quantum Structure Research Team

Strongly correlated electron systems may exhibit various interesting emergent phenomena such as superconductivity, colossal magneto-resistance, and giant magneto-electric effects.  These emergent phenomena are directly associated with the spatial distributions as well as the spatial and temporal fluctuations of atoms, electron density, and spin density.  We are going to perform crystallographic and magnetic structure analyses, spectroscopies, and microscopies by using synchrotron x-rays, neutrons, and high-energy electron beams to reveal them.

Research Fields

Physics / Materials Sciences

Research Subjects

• X-ray-, neutron-, and electron-diffraction studies of superstructure in lattice, charge, orbital, and spin degrees of freedom in strongly-correlated electron systems
• X-ray and neutron spectroscopies of temporal and spatial fluctuations in lattice, charge, orbital, and spin degrees of freedom in strongly-correlated electron systems
• Real-space imaging of heterogeneous structures in strongly correlated electron systems by using x-ray and electron beams

Publications

1. * T. Arima:
   "Time-Reversal Symmetry Breaking and Consequent Physical Responses Induced by All-In-All-Out Type Magnetic Order on the Pyrochlore Lattice"
   J. Phys. Soc. Jpn. 82, 013705(1)-(4) (2013).
2. * Y. Tokunaga, Y. Taguchi, T, Arima, Y. Tokura:
   "Electric-field-induced generation and reversal of ferromagnetic moment in ferrites"
   Nature Physics 8, 838-844 (2012).
3. * S. Fujiyama, K. Ohashi, H. Ohsumi, K. Sugimoto, T. Takayama, T. Komesu, M. Takata, T. Arima, H. Takagi:
   "Weak antiferromagnetism of Jeff=1/2 band in bilayer iridate Sr₃Ir₂O₇"
   Phys. Rev. B 86, 174414(1)-(5) (2012).
4. * N. Kanazawa, J.-H. Kim, D. S. Inosov, J. S. White, N. Egetenmeyer, J. L. Gavilano, S. Ishiwata, Y. Onose, T. Arima, B. Keimer, Y. Tokura:
   "Possible skyrmion-lattice ground state in the B20 chiral-lattice magnet MnGe as seen via small-angle neutron scattering"
   Phys. Rev. B 86, 134425(1)-(7) (2012).
5. * Y. Nii, H. Sagayama, T. Arima, S. Aoyagi, R. Sakai, S. Maki, E. Nishibori, H. Sawa,
   K. Sugimoto, H. Ohsumi, M. Takata:
   "Orbital structures in spinel vanadates AV₂O₄ (A=Fe, Mn)"
   Phys. Rev. B 86, 125142(1)-(8) (2012).
6. * H. Sakai, J. Fujioka, T. Fukuda, M. S. Bahramy, D. Okuyama, R. Arita, T. Arima, A. Q. R. Baron, Y. Taguchi, Y. Tokura:
   "Soft phonon mode coupled with antiferromagnetic order in incipient-ferroelectric Mott insulators Sr_1-xBa_xMnO₃"
   Phys. Rev. B 86, 104407(1)-(11) (2012).
7. * D. Morikawa, K. Tsuda, Y. Maeda, S. Yamada, T. Arima:
   "Charge and Orbital Order Patterns in an A-Site Ordered Perovskite-Type Manganite SmBaMn₂O₆ Determined by Convergent-Beam Electron Diffraction"
   J. Phys. Soc. Jpn. 81, 093602(1)-(4) (2012).
8. * S. Fujiyama, H. Ohsumi, T. Komesu, J. Matsuno, B. J. Kim, M. Takata, T. Arima, H. Takagi:
   "Two-Dimensional Heisenberg Behavior of Jeff=1/2 Isospins in the Paramagnetic State of the Spin-Orbital Mott Insulator Sr₂IrO₄"
   Phys. Rev. Lett. 108, 247212(1)-(5) (2012).
9. * J. Yamaura, K. Ohgushi, H. Ohsumi, T. Hasegawa, I. Yamauchi, K. Sugimoto, S. Takeshita, A. Tokuda, M. Takata, M. Udagawa, M. Takigawa, H. Harima, T. Arima, Z. Hiroi:
   "Tetrahedral Magnetic Order and the Metal-Insulator Transition in the Pyrochlore Lattice of Cd₂Os₂O₇"
   Phys. Rev. Lett. 108, 247205(1)-(5) (2012).
10. * H. Sakai, J. Fujioka, T. Fukuda, D. Okuyama, D. Hashizume, F. Kagawa, H. Nakao, Y. Murakami, T. Arima, A. Q. R. Baron Y. Taguchi, Y. Tokura:
    "Displacement-Type Ferroelectricity with Off-Center Magnetic Ions in Perovskite Sr_1-xBa_xMnO₃"
    Phys. Rev. Lett. 107, 137601(1)-(5) (2011).