Spin Excitation in Coupled Honeycomb Lattice Ni2_2InSbO6_6

We performed an inelastic neutron scattering experiment on a polycrystalline sample of a helimagnet Ni$_2$InSbO$_6$ to construct the spin Hamiltonian. Well-defined spin-wave excitation with a band energy of 20 meV was observed below $T_{N} = 76$ K. Using the linear spin-wave theory, the spectrum was reasonably reproduced with honeycomb spin layers coupled along the stacking axis (the $c$ axis). The proposed spin model reproduces the soliton lattice induced by a magnetic field applied perpendicular to the $c$ axis.Comment: 8 pages, 5 figure

A new inelastic neutron spectrometer HODACA

A new multiplex-type inelastic neutron scattering spectrometer, HOrizontally Defocusing Analyzer Concurrent data Acquisition spectrometer (HODACA), was recently developed and built at the C1-1 cold neutron beam port in JRR-3. The spectrometer is suitable for dynamics measurements in the energy range of $-1$ meV $\lesssim \hbar \omega \lesssim$ 7 meV, catering to a broad array of research fields in physics and material science. HODACA combines 24 detectors and 132 pieces of analyzer crystals and has an estimated measurement efficiency that is 70 times greater than the existing conventional triple-axis spectrometer at the C1-1 beam port. The concept, design, specification, and results of commissioning experiments are described.Comment: 11 pages, 16 figure