208 citations · 262 across the 5 of their papers we have counts for
5 papers
Ground-state phase diagram of spin- Kitaev-Heisenberg models
Kiyu Fukui, Yasuyuki Kato, Joji Nasu +1
The Kitaev model, whose ground state is a quantum spin liquid (QSL), was originally conceived for spin moments on a honeycomb lattice. In recent years, the model has been e…
Resonating Valence-Bond State in an Orbitally Degenerate Quantum Magnet with Dynamical Jahn-Teller Effect
Joji Nasu, Sumio Ishihara
Short-range resonating-valence bond states in an orbitally degenerate magnet on a honeycomb lattice is studied. A quantum-dimer model is derived from the Hamiltonian which represen…
Vaporization of Kitaev spin liquids
Joji Nasu, Masafumi Udagawa, Yukitoshi Motome
Quantum spin liquid is an exotic quantum state of matter in magnets. This state is a spin analogue of the liquid helium which does not solidify down to the lowest temperature due t…
Spin-orbit coupling in octamers in a spinel sulfide CuIrS: Competition between spin-singlet and quadrupolar states, and its relevance to remnant paramagnetism
Joji Nasu, Yukitoshi Motome
We theoretically investigate magnetic properties in the low-temperature phase with the formation of eight-site clusters, octamers, in the spinel compound CuIrS. The octamer…
Ordering and Excitation in Orbital Compass Model on a Checkerboard Lattice
Joji Nasu, Synge Todo, Sumio Ishihara
We study an orbital compass model on a checkerboard lattice where orbital degree of freedom is represented by the pseudo-spin operator. Competition arises from an Ising interaction…