Condensed Matter Theory Laboratory

We aim to understand theoretically various properties of materials of macroscopic scale from the physical laws that govern microscopic world. Many-electron systems having infinite degrees of freedom exhibit rich physical phenomena: they can have phases with spontaneously broken symmetry and transitions among these phases. A typical example is offered by magnetism and superconductivity in strongly-correlated electron systems, such as transition metal oxides and molecular conductors, which are the main research subjects of our laboratory. Our recent research subjects include unconventional ordered states and spin liquids in strongly frustrated quantum magnets and other new kinds of quantum phases like topological insulators and topological superconductors. Furthermore, we study quantum phenomena in mesoscopic systems of nanometer scale and statistical physics of random systems.

Research Subjects

• Strongly-correlated electron systems
• Quantum phase transitions
• Mesoscopic systems

Publications

1. Momoi, T., Sindzingre, P., Kubo, K.:
   "Spin nematic order in multiple-spin exchange models on the triangular lattice"
   Phys. Rev. Lett., 108, 057206 (2012)
   
2. Tanaka, Y., Furusaki, A., Matveev, K.A.:
   "Conductance of a helical edge liquid coupled to a magnetic impurity"
   Phys. Rev. Lett., 106, 236402 (2011)
   
3. Yoshioka, H., Tsuchiizu, M., Otsuka, Y., Seo, H.:
   "Finite-temperature properties across the charge ordering transition -- combined bosonization, renormalization group, and numerical methods"
   J. Phys. Soc. Jpn., 79, 094714 (2010)
   
4. Onoda, S., Tanaka, Y.:
   "Quantum melting of spin ice: emergent cooperative quadrupole and chirality"
   Phys. Rev. Lett., 105, 047201 (2010)
   
5. Schnyder, A.P., Ryu, S., Furusaki, A., Ludwig, A.W.W.:
   "Classification of topological insulators and superconductors in three spatial dimensions"
   Phys. Rev. B, 78, 195125 (2008)
   
6. Hikihara, T., Kecke, L., Momoi, T., Furusaki, A.:
   "Vector chiral and multipolar orders in the spin-1/2 frustrated ferromagnetic chain in magnetic field"
   Phys. Rev. B, 78, 144404 (2008)
   
7. Matveev, K.A., Furusaki, A., Glazman, L.I.:
   "Bosonization of strongly interacting one-dimensional electrons"
   Phys. Rev. B, 76, 155440 (2007)
   
8. Ryu, S., Mudry, C., Obuse, H., Furusaki, A.:
   "Z2 topological term, the global anomaly, and the two-dimensional symplectic symmetry class of Anderson localization"
   Phys. Rev. Lett., 99, 116601 (2007)
   
9. Obuse, H., Subramaniam, A.R., Furusaki, A., Gruzberg, I.A., Ludwig, A.W.W.:
   "Multifractality and conformal invariance at 2D metal-insulator transition in the spin-orbit symmetry class"
   Phys. Rev. Lett., 98, 156802 (2007)
   
10. Shannon, N., Momoi, T., Sindzingre, P.:
    "Nematic order in square lattice frustrated ferromagnets"
    Phys. Rev. Lett., 96, 027213 (2006).