Determination of localized surface phonons in nanocrystalline silicon by inelastic neutron scattering spectroscopy and its application to deuterium isotope enrichment

Matsumoto, Takahiro*; Nomata, Ikumi*; Ohara, Takashi; Kanemitsu, Yoshihiko*

Physical Review Materials (Internet), 5(6), p.066003_1 - 066003_9, 2021/06

https://doi.org/10.1103/PhysRevMaterials.5.066003

Quantum twin spectra in nanocrystalline silicon

Matsumoto, Takahiro*; Ohara, Takashi; Sugimoto, Hidehiko*; Bennington, S. M.*; Ikeda, Susumu*

Physical Review Materials (Internet), 1(5), p.051601_1 - 051601_6, 2017/10

https://doi.org/10.1103/PhysRevMaterials.1.051601

Three-dimensional electronic structure and multiple superconducting gaps of BaKFeAs as seen via time-of-flight neutron spectroscopy

Kajimoto, Ryoichi; Kofu, Maiko; Kawamura, Seiko; Suzuki, Katsuhiro*; Nakajima, Masamichi*; Murai, Naoki

no journal, , 

The spin dynamics of iron-based superconductors is believed to play an essential role in the pairing mechanism, but realistic modeling of magnetic neutron scattering spectra in these materials remains challenging owing to their complex multi-band structure. Here we report the results of inelastic neutron scattering measurements of BaKFeAs that provide a benchmark of an ab-initio approach of the dynamical spin susceptibility. Our main results are two-fold. First, the magnetic neutron scattering response exhibits periodic intensity modulation along the out-of-plane direction. The observed periodicity corresponds to the out-of-plane warping of Fermi surfaces, revealing the importance of nesting in three-dimensional momentum space. Second, our careful measurements reveal the existence of the theoretically predicted multiple resonant modes that result from the multiple superconducting gaps. The agreement between theory and experiment in the present work highlights the potential of neutron spectroscopy to investigate the complex multi-band structure of iron-based superconductors.