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Kotegawa, Hisashi*; Nakamura, Akira*; Huyen, V. T. N.*; Arai, Yuki*; To, Hideki*; Sugawara, Hitoshi*; Hayashi, Junichi*; Takeda, Keiki*; Tabata, Chihiro; Kaneko, Koji; et al.
Physical Review B, 110(21), p.214417_1 - 214417_8, 2024/12
Times Cited Count：0 Percentile：0.00(Materials Science, Multidisciplinary)Takagi, Hirotaka*; Takagi, Rina*; Minami, Susumu*; Nomoto, Takuya*; Oishi, Kazuki*; Suzuki, Michito*; Yanagi, Yuki*; Hirayama, Motoaki*; Khanh, N.*; Karube, Kosuke*; et al.
Nature Physics, 19(7), p.961 - 968, 2023/07
Times Cited Count：50 Percentile：99.07(Physics, Multidisciplinary)
-US
Metoki, Naoto; Sakai, Hironori; Suzuki, Michito; Yamamoto, Etsuji; Haga, Yoshinori; Matsuda, Tatsuma; Ikeda, Shugo*
JPS Conference Proceedings (Internet), 3, p.013011_1 - 013011_6, 2014/06
Uranium chalcogenides are highly interesting because of the variety of the physical properties from 5
-based metal and Mott-Hibbard insulator. Especially dichalcogenide family exhibits a metal-insulator crossover depending on the chalcogenide elements, or under magnetic field and pressure. In this talk we present a recent result of our neutron scattering study on uranium dichalcogenide, which demonstrates that the metal-insulator crossover is related to the change of 5 character from localized to itinerant. The electronic structure related to this phenomenon is discussed based on the band calculation.
Si; High magnetic field nuclear magnetic resonance to 40 TSakai, Hironori; Urbano, R. R.*; Tokunaga, Yo; Kambe, Shinsaku; Suzuki, Michito; Kuhns, P. L.*; Reyes, A. P.*; Tobash, P. H.*; Ronning, F.*; Bauer, E. D.*; et al.
Physical Review Letters, 112(23), p.236401_1 - 236401_5, 2014/06
Times Cited Count：7 Percentile：47.25(Physics, Multidisciplinary)Very high field 
Si-NMR measurements using a fully Si-enriched URuSi single crystal were carried out in order to microscopically investigate the "hidden order" (HO) state and adjacent magnetic phases in the high field limit. At the lowest measured temperature of 0.4 K, a clear anomaly reflecting a Fermi surface instability near 22 T inside the HO state is detected by the Si shift, 
. Moreover, a strong enhancement of develops near a critical field 
T, and the Si-NMR signal disappears suddenly at 
, indicating the total suppression of the HO state. Nevertheless, a weak and shifted Si-NMR signal reappears for fields higher than at 4.2 K, providing evidence for a magnetic structure within the magnetic phase caused by the Ising-type anisotropy of the uranium ordered moments.
(An=U, Np, Pu, Am, and Cm)Suzuki, Michito; Magnani, N.*; Oppeneer, P.*
Physical Review B, 88(19), p.195146_1 - 195146_14, 2013/11
Times Cited Count：53 Percentile：85.94(Materials Science, Multidisciplinary)Recently, f electron materials containing actinide elements have drawn considerable interest, stimulated by observations of intriguingly ordered ground states forming at low temperatures. In this study, we performed a systematic analysis of the electronic ground states of actinide dioxides AnO (An=U, Np, Pu, Am, and Cm) on the basis of a state-of-art first-principles method developed by the authors. The calculations provide intuitive connections between the electronic structures and the local crystalline fields working on the 5 states in the AnO series. Particularly the mechanisms leading to the experimentally observed insulating ground states are investigated. These are found to arise from the strong spin-orbit and Coulomb interactions of the 5 orbitals. However, as a result of the different 5 configurations, these interactions work in distinctly different ways for each of the AnO compounds.
AlCKoyama, Takehide*; Ozaki, Yuzuru*; Ueda, Koichi*; Mito, Takeshi*; Kohara, Takao*; Waki, Takeshi*; Tabata, Yoshikazu*; Michioka, Chishiro*; Yoshimura, Kazuyoshi*; Suzuki, Michito; et al.
Journal of the Physical Society of Japan, 81(Suppl.B), p.SB008_1 - SB008_5, 2012/12
Times Cited Count：1 Percentile：10.43(Physics, Multidisciplinary)The normal state properties of a noncentrosymmetric superconductor MoAlC are studied by means of the nuclear magnetic resonance (NMR) experiment. The change of NMR line shape and the peak of the nuclear spin-echo decay rate at 
130 K indicate that the MoAlC exhibits the phase transition prior to the emergence of superconductivity. The reduction in the conduction electron density is inferred from the decrease in the nuclear spin-lattice relaxation rate. The nature of the newly found phase transition is discussed by considering the result of the first principle calculations, indicating a good nesting property of the Fermi surfaces.
Si with an itinerant electron pictureIkeda, Hiroaki*; Suzuki, Michito
Kotai Butsuri, 47(11), p.693 - 706, 2012/11
no abstracts in English
SiIkeda, Hiroaki*; Suzuki, Michito; Arita, Ryotaro*; Takimoto, Tetsuya*; Shibauchi, Takasada*; Matsuda, Yuji*
Nature Physics, 8(7), p.528 - 533, 2012/07
Times Cited Count：138 Percentile：95.92(Physics, Multidisciplinary)The origin of the hidden-order phase transition of URuSi has been a long-standing mystery in condensed matter physics. We examine the complete set of multipole correlations allowed in URuSi based on a first-principles theoretical approach. The results uncover that the hidden-order parameter is a rank-5 multipole (dotriacontapole) order with nematic 
symmetry. This naturally provides comprehensive explanations of all key features in the hidden-order phase including anisotropic magnetic excitations, nearly degenerate antiferromagnetic-ordered state, and spontaneous rotational symmetry breaking.
AlCKoyama, Takehide*; Ozaki, Yuzuru*; Ueda, Koichi*; Mito, Takeshi*; Kohara, Takao*; Waki, Tsuyoshi*; Tabata, Yoshikazu*; Michioka, Chishiro*; Yoshimura, Kazuyoshi*; Suzuki, Michito; et al.
Physical Review B, 84(21), p.212501_1 - 212501_4, 2011/12
Times Cited Count：13 Percentile：47.75(Materials Science, Multidisciplinary)The results of 
Al nuclear magnetic resonance and specific-heat measurements of the noncentrosymmetric superconductor MoAlC are reported. The phase transition around 130 K is inferred from a distinct change in the NMR spectrum, a clear peak in the spin-echo decay rate, and an anomaly in the specific heat. Possibility of charge-density wave ordering around 130 K is discussed by calculating the Fermi surfaces in the normal states and considering the partial quenching of the Fermi surfaces with the decrease in 1/
below the superconducting transition temperature.
Ijiri, Yuji*; Suzuki, Shunichi*; Sugihara, Yutaka*; Shimo, Michito*; Yamamoto, Hajime*;
JNC TJ7400 2002-003, 525 Pages, 2002/03
JNC-TJ7400-2002-003.pdf:15.78MB
no abstracts in English
Ijiri, Yuji*; Suzuki, Shunichi*; Oishi, Masaya*; Sugihara, Yutaka*; Shimo, Michito*; ;
JNC TJ7400 2001-007, 612 Pages, 2001/03
JNC-TJ7400-2001-007.pdf:118.17MB
no abstracts in English
-USMetoki, Naoto; Sakai, Hironori; Suzuki, Michito; Yamamoto, Etsuji; Haga, Yoshinori; Matsuda, Tatsuma; Ikeda, Shugo*
no journal, ,
We report the magnetic excitation in a narrow gap semiconductor -US taken by means of neutron scattering. At low temperatures clear crystalline electric field (CEF) excitations were observed, indicating localized character of 5 electrons. The excitation energy 
7 meV of the pseudo doublet state is consistent with the level scheme based on 5
configuration of U
ions, which reproduces the magnetic susceptibility, magnetization, and specific heat. With elevating temperature the conductivity recovers with 5 carriers excited beyond the gap of 90 K. Simultaneously the CEF excitation becomes weak and broad, and is replaced by a quasi-elastic response of magnetic origin, indicating the crossover of 5 character from localized to itinerant. The physical properties including present magnetic excitation study will be discussed with the results of band calculation study.
Suzuki, Michito
no journal, ,
The praseodymium compounds which have non-Kramers type doublet crystal field ground states, known to show no split under the magnetic fileds, are interested in the electronic properties of the quadrupolar ordered ground states. For instance, PrPtBi undergoes a quadrupolar phase transition at 1.35K and is considered to have semiconducting property, but the order parameter and insulating mechanism have yet to be elucidated. Other example is PrPb
, which undergo a quadrupolar phase transition at 0.4 K. In this compound, while the incommensurate order of the quadrupoles under the weak magnetic fields has been reported experimentally, detailed ordered state has yet to be determined. We will discuss the electronic properties of the electronic ordered ground states based on the first-principles calculations.
character in -US, a Mott insulator with a narrow 
- hybridization gapMetoki, Naoto; Sakai, Hironori; Suzuki, Michito; Yamamoto, Etsuji; Haga, Yoshinori; Matsuda, Tatsuma; Ikeda, Shugo*
no journal, ,
It is revealed that the localized 5
state is stable at low temperature in US from the observation of crystal-field excitation. The crystal field excitation is strongly dumped and a magnetic quasi-elastic scattering is observed with decrease of the electrical resistivity in the order of 10
above 100 K. This is understood with the crossover of 5 electrons from the localized to the itinerant character. The band calculation by Suzuki 
. reported that US is a Mott insulator with a small - hybridization gap in the vicinity of the 
point. Therefore the crossover of 5 character is considered to be due to the hybridization effect, although the presence of the impurity level can not be ruled out experimentally.
-US, a Mott insulator with a narrow - hybridization gapMetoki, Naoto; Sakai, Hironori; Suzuki, Michito; Yamamoto, Etsuji; Haga, Yoshinori; Matsuda, Tatsuma; Ikeda, Shugo*
no journal, ,
Our neutron scattering study revealed the crossover of the 5 character in -US. This compound is a Mott insulator with a small - hybridization gap at point. The hybridization effect with a peculiar band dispersion nearly Dirac fermion would be the origin of the crossover of 5 character.
-states and Fermi surfaces in strongly correlated f-electron compoundsSuzuki, Michito
no journal, ,
Formation of electronic states with strong electron correlation expressed in a multi spin-orbital space is one of the main subjects of actinide materials. Especially, a huge variety of f states observed in the actinide compounds are most attractive subject of research to figure out the multi orbital physics. I introduce recent electronic structure studies for strongly correlated electron compounds with several types of ground states to understand how the states affect to the states around the Fermi level in these compounds. It is expected that the research outcomes greatly develop the ability of prediction for the material properties.
(An=U, Np, Pu, Am, and Cm)Suzuki, Michito; Oppeneer, P.*; Magnani, N.*
no journal, ,
The electronic ground states of the actinide dioxides AnO (with An=U, Np, Pu, Am, and Cm) are investigated employing first-principles calculations. In agreement with experimental observations, the nonmagnetic states of plutonium and curium dioxide are computed to be insulating, whereas the uranium, neptunium and americium dioxides require symmetry breaking, a condition which is met with magnetic phase transitions, to reproduce the insulator ground states. We show that the occupancy of the An- orbitals is closely connected to each of the appearing insulating mechanisms. We furthermore investigate the detailed constitution of multipolar moments for transverse 3
magnetic ordered states in UO and longitudinal 3 high-rank multipolar ordered states in NpO and AmO.
Suzuki, Michito
no journal, ,
no abstracts in English
Suzuki, Michito
no journal, ,
A variety of ordered states produced in a lot of lanthanoid and actinoide compounds are a important topic to understand complex physica phenomena observed in these compounds. In this oral presentation, we report a recent developments of our study about an electronic states and the magnetic space symmetry of lanthanoid and actinoide compounds. We especially focus on multipole ordered phases in NpO and URuSi and cant-ferro magnetic ordered states in Uran di-chalcogenides based on a relation between the magnetic space symmetry and the electronic states. It is expected that these study make substantial progress in terms of understanding of a variety of physical phenomena, not yet to be understood, in newly found lanthanoid and actinoide materials.
Suzuki, Michito
no journal, ,
no abstracts in English
