Nested antiferromagnetic spin fluctuations and non-Fermi-liquid behavior in electron-doped CeCoNiIn

Sakai, Hironori; Tokunaga, Yo; Kambe, Shinsaku; Zhu, J.-X.*; Ronning, F.*; Thompson, J. D.*; Kotegawa, Hisashi*; To, Hideki*; Suzuki, Kohei*; Oshima, Yoshiki*; et al.

Physical Review B, 106(23), p.235152_1 - 235152_8, 2022/12

https://doi.org/10.1103/PhysRevB.106.235152

We investigate the electronic state of Ni-substituted CeCoNiIn by nuclear quadrupole and magnetic resonance (NQR/NMR) techniques. The heavy fermion superconductivity below K for is suppressed by Ni substitutions, and reaches zero for . The In NQR spectra for and 0.25 can be explained by simulating the electrical field gradient that is calculated for a virtual supercell with density functional theory. The spin-lattice relaxation rate indicates that Ni substitution weakens antiferromagnetic correlations that are not localized near the substituent but instead are uniform in space. The temperature () dependence of for shows a maximum around K and decreases toward almost zero when temperature is further reduced as if a gap might be opening in the magnetic excitation spectrum; however, the magnetic specific heat and the static magnetic susceptibility evolve smoothly through with a dependence. The peculiar T dependence of and non-Fermi-liquid specific heat and susceptibility can be interpreted in a unified way by assuming nested antiferromagnetic spin fluctuations in a quasi-two-dimensional electronic system.

Screw dislocation-spherical void interactions in fcc metals and their dependence on stacking fault energy

Hayakawa, Sho*; Doihara, Kohei*; Okita, Taira*; Itakura, Mitsuhiro; Aichi, Masaatsu*; Suzuki, Katsuyuki*

Journal of Materials Science, 54(17), p.11509 - 11525, 2019/09

https://doi.org/10.1007/s10853-019-03716-0

Atomic simulations to evaluate effects of stacking fault energy on interactions between edge dislocation and spherical void in face-centred cubic metals

Doihara, Kohei*; Okita, Taira*; Itakura, Mitsuhiro; Aichi, Masaatsu*; Suzuki, Katsuyuki*

Philosophical Magazine, 98(22), p.2061 - 2076, 2018/05

https://doi.org/10.1080/14786435.2018.1472401

In this study, molecular dynamics simulations were performed to elucidate the effects of stacking fault energy (SFE) on the physical interactions between an edge dislocation and a spherical void in the crystal structure of face-centred cubic metals at various temperatures and for different void sizes. Four different types of interaction morphologies were observed, in which (1) two partial dislocations detached from the void separately, and the maximum stress corresponded to the detachment of the trailing partial; (2) two partial dislocations detached from the void separately, and the maximum stress corresponded to the detachment of the leading partial; (3) the partial dislocations detached from the void almost simultaneously without jog formation; and (4) the partial dislocations detached from the void almost simultaneously with jog formation. With an increase in void size or SFE, the interaction morphology changed in the above-mentioned order. It was observed that the magnitude of the critical resolved shear stress (CRSS) and its dependence on the SFE were determined by these interaction morphologies. The value of the CRSS in the case of interaction morphology (1) is almost equal to an analytical one based on the linear elasticity by employing the Burgers vector of a single partial dislocation. The maximum value of the CRSS is also obtained by the analytical model with the Burgers vector of the two partial dislocations.

Deep microbial life in high-quality granitic groundwater from geochemically and geographically distinct underground boreholes

Ino, Kohei*; Konno, Yuta*; Kozuka, Mariko*; Hirota, Akinari*; Togo, Yoko*; Fukuda, Akari*; Komatsu, Daisuke*; Tsunogai, Urumu*; Tanabe, Akifumi*; Yamamoto, Satoshi*; et al.

Environmental Microbiology Reports (Internet), 8(2), p.285 - 294, 2016/04

https://doi.org/10.1111/1758-2229.12379

To understand the subsurface biosphere, borehole investigation was conducted for 300-m deep granitic rocks at the Mizunami underground research laboratory, Japan. The initial biomass was the highest with the flourish of aerobic H-oxidizing Hydrogenophaga spp., whereas an uncultivated lineage of the phylum Nitrospirae became predominant after three years with decreasing biomass. The common occurrence of many species of Nitrospirae and Chlorobi phyla at the geographically distinct sites and the exclusive detection of their phylogenetically related environmental sequences from deep groundwaters and terrestrial hot springs, suggest that these bacteria are indigenous and potentially adapted to the deep terrestrial subsurface.

Full-scale 3D vibration simulator for an entire nuclear power plant on the simple orchestration application framework

Kim, G.; Nakajima, Kohei*; Teshima, Naoya; Tatekawa, Takayuki; Suzuki, Yoshio; Takemiya, Hiroshi

Proceedings of Joint International Conference of 7th Supercomputing in Nuclear Application and 3rd Monte Carlo (SNA + MC 2010) (USB Flash Drive), 5 Pages, 2010/10

Full-Scale 3D vibration simulator for an entire nuclear power plant is a seismic response analysis system for a whole digitalized nuclear power plant. In the system, boundary data from large components are used as input data of small components. To make a whole simulation efficient, we introduced pipeline method in which the data were transferred each time step running all components simulations in parallel. In the realization of the method on grid, since there were no existing grid technologies to sufficiently support the method for a long time, we developed simple orchestration application framework (SOAF) and using the SOAF, we performed seismic response analysis of a test reactor of JAEA and succeeded simulation for a week.

Simple orchestration application framework to control "Burning Plasma Integrated Code"

Tatekawa, Takayuki; Nakajima, Kohei*; Teshima, Naoya; Kim, G.; Suzuki, Yoshio; Takemiya, Hiroshi; Hayashi, Nobuhiko; Iba, Katsuyuki*

Proceedings of 3rd International Joint Conference on Computational Sciences and Optimization (CSO 2010), p.322 - 326, 2010/05

Data exploration system for the evaluation of numerical simulation results

Miyamura, Hiroko; Nakajima, Kohei*; Suzuki, Yoshio; Hayashi, Sachiko; Takemiya, Hiroshi; Nakajima, Norihiro

Zen NEC C&C Shisutemu Yuza Kai Heisei-21-Nendo Rombunshu (CD-ROM), 12 Pages, 2010/02

In this paper, we propose data exploration system for the evaluation of numerical simulation results. With the improvement in the performance of supercomputers, numerical simulations have become larger and more complex, which has made the interpretation of simulation results more difficult. Moreover, occasionally, users cannot evaluate numerical simulation results, even though they have spent a great deal of time, because interactive visualization is impossible for such large-scale data. Therefore, we herein propose a data exploration system with which users evaluate large-scale time-series data that has been obtained in a parallel and distributed environment. The proposed system allows users to simultaneously visualize and analyze data in both the global and local scales.

Interoperation between Atomic Energy Grid Infrastructure (AEGIS) and other grids

Suzuki, Yoshio; Kushida, Noriyuki; Teshima, Naoya; Nakajima, Kohei; Nishida, Akemi; Nakajima, Norihiro

High Performance Computing on Vector Systems 2008, p.65 - 77, 2009/00

Center for computational science and e-systems, Japan Atomic Energy Agency (CCSE/JAEA) has been carrying out R&Ds of grid computing technology since FY1995 aiming at establishing an infrastructure for the computational science research. One of them is R&D of IT-Based Laboratory (ITBL) infrastructure. The ITBL project is a national project placed as one of the e-Japan Priority Policy Program to realize the e-Japan Strategy. By succeeding the technology of ITBL infrastructure, CCSE is carrying out R&D of Atomic Energy Grid Infrastructure (AEGIS) to construct an intelligent infrastructure for the atomic energy research. CCSE has been carrying out international cooperation researches in various fields to advance computer science and to expand AEGIS grid computing environment. To achieve this, we have developed the system to construct interoperable environments between AEGIS and other grid middleware.

MUSIC in DEEP; ()lti-monitoring ()elf ()nteraction ()ondition in ()ata ()xplorer for ()valuation ()rocessing

Nakajima, Norihiro; Araya, Fumimasa; Suzuki, Yoshio; Nishida, Akemi; Matsubara, Hitoshi; Nakajima, Kohei

Dai-27-Kai Nihon Shimyureshon Gakkai Taikai Happyo Rombunshu, p.511 - 514, 2008/06

A real space simulator for vibration table targeted to a nuclear power station has been proposed, which generates over tera-byte amount of calculated result. In order to analyze a huge size data, a data analyzer and data analyzing monitor system is suggested in this paper. A result of finite element analysis is examined by the system taking into account relation among neighboring elements' results. It is operated by multi-monitoring to view analyzing process. The system is implemented on a grid computing environment, AEGIS (atomic energy grid infrastructure) with coupling a large data visualization system.

Research and development of fusion grid infrastructure based on Atomic Energy Grid InfraStructure (AEGIS)

Suzuki, Yoshio; Nakajima, Kohei; Kushida, Noriyuki; Kino, Chiaki; Aoyagi, Tetsuo; Nakajima, Norihiro; Iba, Katsuyuki*; Hayashi, Nobuhiko; Ozeki, Takahisa; Totsuka, Toshiyuki; et al.

Fusion Engineering and Design, 83(2-3), p.511 - 515, 2008/04

https://doi.org/10.1016/j.fusengdes.2007.09.017

In collaboration with the Naka Fusion Institute of Japan Atomic Energy Agency (NFI/JAEA) and the National Institute for Fusion Science of National Institute of Natural Science (NIFS/NINS), Center for Computational Science and E-systems of Japan Atomic Energy Agency (CCSE/JAEA) aims at establishing an integrated framework for experiments and analyses in nuclear fusion research based on the Atomic Energy Grid InfraStructure (AEGIS). AEGIS has been being developed by CCSE/JAEA aiming at providing the infrastructure that enables atomic energy researchers in remote locations to carry out R&D efficiently and collaboratively through the Internet. Toward establishing the integrated framework, we have been applying AEGIS to pre-existing three systems.