Computational Condensed Matter Physics Laboratory

Our main aim is to theoretically understand various novel quantum phases and phenomena in a wide range of materials by microscopically studying their electronic structures. One of our main interests includes strongly correlated electron systems such as different kinds of transition metal oxides and low-dimensional organic conductors. Using various state-of-the-art numerical methods, we study the novel ground states, low-lying collective excitations, and quantum transport properties in these systems. We are also very much interested in applying variational Monte Carlo method and density matrix renormalization group method to search a possible new spin liquid in two spatial dimensions and study the topological properties (such as quantum entanglement) of various topological ordered states including spin liquids. We are also eager to develop new numerical methods for quantum many-body systems in general.

Research Subjects

• Quantum states and quantum dynamics in strongly correlated systems
• Qunatum liquid states in quantum spin systems
• New numerical methods for strongly correlated quantum many-body systems

Publications

1. H. Watanabe, T. Shirakawa, and S. Yunoki.:
   "Monte Carlo study of an unconventional superconducting phase in Iridium oxide Jeff = 1/2 Mott insulators induced by carrier doping"
   Phys. Rev. Lett. 110, 027002 (2013)
2. S. Sorella, Y. Otsuka, and S. Yunoki.:
   "Absence of a spin liquid phase in the Hubbard model on the honeycomb lattice"
   Scientific Reports 2, 992 (2012)
3. Q. Zhang, S. Dong, B. Wang, and S. Yunoki.:
   "Strain-engineered magnetic order in (LaMnO3)n/(SrMnO3)2n superlattices"
   Phys. Rev. B 86, 094403 (2012)
4. Q. Zhang, S. Hikino, and S. Yunoki.:
   "First-principles study of the spin-mixing conductance in Pt/Ni81Fe19 junctions"
   Appl. Phys. Lett. 99, 172105 (2011)
5. Y. Sun, X.-Q. Chen, C. Franchini, D. Li, S. Yunoki, Y. Li, and Z. Fang.:
   "Strain-driven onset of nontrivial topological insulating states in Zintl Sr2X compounds (X=Pb, Sn)"
   Phys. Rev. B 84, 165127 (2011)
6. S. Hikino and S. Yunoki.:
   "Anomalous enhancement of spin Hall conductivity in a superconductor/normal-metal junction"
   Phys. Rev. B 84, 020512(R) (2011)
7. H. Watanabe, T. Shirakawa, and S. Yunoki.:
   "Microscopic study of a spin-orbit-induced Mott insulator in Ir oxides"
   Phys. Rev. Lett. 105, 216410 (2010)
8. Y. Sun, X.-Q. Chen, S. Yunoki, D. Li, and Y. Li.:
   "New family of three-dimensional topological insulators with antiperovskite structure"
   Phys. Rev. Lett. 105, 216406 (2010)
9. Y. Sun, X.-Q. Chen, S. Yunoki, D. Li, and Y. Li.:
   "New family of three-dimensional topological insulators with antiperovskite structure"
   Phys. Rev. Lett. 105, 216406 (2010)
10. S. Yunoki and S. Sorella.:
    "Resonating valence bond wave function for the two-dimensional fractional spin liquid"
    Phys. Rev. Lett. 92, 157003 (2004)