多元環境下の強相関電子相

2000 Fiscal Year Annual Research Report

• Project/Area Number: 10CE2004
• Research Institution: Osaka University
• Principal Investigator: 三宅 和正 大阪大学, 大学院・基礎工学研究科, 教授 (90109265)
• Co-Investigator(Kenkyū-buntansha): 伊藤 正 大阪大学, 大学院・基礎工学研究科, 教授 (60004503) ; 大貫 惇睦 大阪大学, 大学院・理学研究科, 教授 (40118659) ; 北岡 良雄 大阪大学, 大学院・基礎工学研究科, 教授 (70110707) ; 天谷 喜一 大阪大学, 大学院・基礎工学研究科, 教授 (80029503) ; 冷水 佐壽 大阪大学, 大学院・基礎工学研究科, 教授 (50201728)
• Keywords: 重い電子系 / 異方的超伝導 / 圧力誘起超伝導 / 超高圧誘起金属絶縁体転移 / メゾスコピック系 / 非線形光学 / 光誘起相転移 / 低次元電子系の伝導現象

Research Abstract

1)強相関電子物性グループ(三宅、北岡、大貫、菅)
量子臨界点の近傍では一般に、不純物散乱の効果が増強を受けることを示し、種々の系で観測される残留抵抗の異常な増大を説明することに成功した。d電子に起因する重い電子系LiV_2O_4の起源を解明した。(三宅)重い電子系に代表される強相関電子系の反強磁性と異方的超伝導との共存と競合を解明した。過剰ドープ高温超伝導体の擬ギャップは、超伝導ゆらぎによることを初めて示した。(北岡)希土類・ウラン系重い電子化合物の純良単結晶を多数育成し、その電子状態をドハース効果を用いて調べた。URu_2Si_2の超伝導混合状態でのドハース効果に関して独創的な結果を得た。(大貫)数百eV以上の高分解能軟X線でバルク敏感な光電子分光に成功した前年度の成果を発展させて、同測定を角度分解で行えるようになった。(菅)
2)閉じ込め電子相関相グループ(伊藤、張、冷水、邑瀬)
GaAs,CuCl量子ドットの単一ドット顕微分光、非線形分光を行い、励起子閉じ込め状態の詳細と量子ドット特有の励起電子多体効果を捉えた。(伊藤)微視的非局所応答理論による「球内閉じ込め励起子の光応答」の一般的枠組み提示と具体例の計算、磁性原子吸着表面での近藤効果とその実空間像、及び「ショックレー状態電子の寿命」における電子相関効果の研究を行った。(張)(221)A InGaAs/N-AlGaAs変調ドープ量子細線の電気的特性を明らかにした。GaAs/N-AlGaAs,InGaAs/N-AlGaAs変調ドープ量子井戸の磁気ホトルミネッセンスから(411)A超平坦ヘテロ界面と(100)界面の界面ラフネスポテンシャルの波数依存性をはじめて評価した。(冷水)2次元電子系(2DES)の量子ホール効果について磁気電気容量法による研究を行い、エッジチャネルが分数QHEでも存在すること、GaAs系・Si-MOSなど異なる物質でも存在することを見いだした。(邑瀬)
3)超高圧電子相グループ(天谷、那須、鈴木)
磁性と超伝導との相関から新しい超伝導機構を探る」という観点から、強磁性鉄での圧力誘起超伝導の観測、強磁性超伝導体UGe_2の圧力下比熱・磁化の測定により超伝導発現機構に知見を加えた。(天谷)実験的に同定されていないリンの250GPa以上における構造について、bcc構造であることを予測した。群論的考察から軌道縮退三角格子系では、軌道の三角配列といった三角格子特有のスピン・軌道の秩序状態が可能であることを示した(鈴木)ダイヤモンド・アンビル・セル(DAC)を用いて、ペロブスカイト型Fe酸化物であるCaFeO_3、La_<1/3>Sr_<2/3>FeO_3の高圧下メスバウアー分光測定を精力的に行い、圧力・温度磁気状態図を完成させた。(那須)

Research Products

• [Publications] Y.Onishi: "Enhanced Valence Fluctuation Caused by f-c Coulomb Interaction in Ce-Based Heavy Electrons : Possible origin of Pressure-Induced Enhancement of Superconducting Temperature in CeCu_2Ge_2 and Related Compounds"J.Phys.Soc.Jpn.. 69. 3955-3964 (2000)
• [Publications] K.Miyake: "A Route to Small Drude Weight in Metals with Nested Spin Fluctuations and Enhaced Impurity Scattering Associated with Quantum Critical Phenomena"J.Phys.Chem.Solids. 62. 53-57 (2001)
• [Publications] Y.Fuseya: "Anomalous Fermi Liquid Effects in Two-Dimensional Hubbard Model near Half-Filling"J.Phys.Soc.Jpn.. 69. 2158-2163 (2000)
• [Publications] N.K.Sato: "Strong Coupling between Local Moments and Superconducting 'Heavy' Electrons UPd_2Al_3"Nature. 410. 340-343 (2001)
• [Publications] K.Miyake: "Unconventional Cooper pairing in the Superconducting State of UPd_2Al_3"Phys.Rev.B. 63. 052508-1-2 (2001)
• [Publications] J.Flouquet: "UGe_2a Ferromagnetic Superconductor"J.Phys.Soc.Jpn.Suppl.,. (in press).
• [Publications] S.Yotsuhashi: "Orbital Dependence in Kondo Effect Enlarged by Hund's-Rule Coupling"J.Phys.Soc.Jpn.. 70. 186-191 (2001)
• [Publications] H.Kusunose: "Formation of heavy quasiparticle state in two-band Hubbard model"Phys.Rev.B. 62. 4403-4407 (2000)
• [Publications] K.Miyake: "Effect of Spin-Orbit Impurity Scatteing on the Knight Shift in BCS Superconductors : Reanalysis of Anderson's Classic Paper"Phys.Rev.B. 62. 11363-11364 (2000)
• [Publications] Y.Tokunaga: "Effect of carrier distribution on superconducting characteristics of multilayered high-Tc cuprate (Cu_<0.6>C_<0.4>)Ba_2Ca_3Cu_4O_<12+y> : ^<63>Cu-NMR study"Phy.Rev.B. 61・14. 9707-9710 (2000)
• [Publications] Y.Tokunaga: "Pseudogap and superconducting fluctuations in Bi_2Sr_2CaCu_2O_<8+y> probed by ^<63>Cu NMR"Physica B. 284-288. 663-664 (2000)
• [Publications] H.Mukuda: "Spin fluctuations in ruthenium oxides probed by Ru-NMR"Physica B. 284-288. 1467-1468 (2000)
• [Publications] K.Ishida: "Anisotropic superconducting gap in the spin-triplet superconductor Sr_2RuO_4 : Evidence from a Ru-NQR study"Phys.Rev.Lett.. 84・23. 5387-5390 (2000)
• [Publications] G.-q.Zheng: "Superconducting fluctuations and the pseudogao in the slightly overdoped high-Tc superconcuctor TlSr_2CaCu_2O_<6.8> : High magnetic field NMR studies"Physical Review Letters. 85・2. 405-408 (2000)
• [Publications] K.Ishida: "Cu-NQR study of magnetism and superconductivity in Ce_<1+x>Cu_<2+y>Si_2 under pressure"Hyperfine Interactions. 128. 193-204 (2000)
• [Publications] G.-q.Zheng: "Spin-gap and the superconducting fluctuations in high-Tc cuprates probed by ^<63>Cu NMR"Journal of Physics and Chemistry of Solids. 62. 25-27 (2001)
• [Publications] Y.Tokunaga: "Spin gap and superconducting fluctuations in Bi_2Sr_2CaCu_2O_<8+δ> probed by ^<63>Cu NMR"Journal of Physics and Chemistry of Solids. 62. 167-170 (2001)
• [Publications] H.Kotegawa: "NMR Study of Carrier distribution and Superconductivity in Multilayered High-Tc Cupretes"J.Phys.and Chem.Solids. 62. 171-175 (2001)
• [Publications] Y.Kitaoka: "Coexistence of superconductivity and antiferromagnetism in the heavy-fermion superconductor CeCu_2(Si_<1-x>Ge_x)_2 probed by means of Cu nuclear quadrupole resonance - a test case for the SO(5) theory"J.Phys. : Condens.Matter. 13・4. L79-L88 (2001)
• [Publications] K.Ishida: "Ru NMR probe of spin susceptibility in the superconducting state of Sr_2RuO_4"Phys.Rev.B. 63. 060507(R)1-4 (2001)
• [Publications] Y.Kawasaki: "Exotic magnetic propertie and superconducting phase in CeCu_2Si_2 close to magnetic phase : A Cu-NQR study under hydrostatic pressure"Phys.Rev.B. (in press).
• [Publications] P.Wisniewski, et al.: "Shubnikov-de Haas Effect Study of Cylindrical Fermi Surfaces in UAs_2"J.Phys.Condens.Matter. 12. 1971-1980 (2000)
• [Publications] Y.Onuki, et al.: "Itinerant f-electron Systems of Cerium and Uranium Sompounds"Physica B. 280. 276-280 (2000)
• [Publications] N.Metoki, et al.: "Neutron Scattering Studies on Heavy-fermion Superconductors"Physica B. 280. 362-367 (2000)
• [Publications] T.C.Kobayashi, et al.: "Pressure-dependence of Superconducting Behavior in CeRh_2Si_2"Physica B. 281&282. 7-8 (2000)
• [Publications] C.Thessieu, et al.: "In-NQR Study of CeIn_3 under Pressure"Physica B. 281&282. 9-11 (2000)
• [Publications] H.Matsui, et al.: "Electrodynamic Response at Metamagnetic Anomaly in CeRu_2Si_2"Physica B. 281&282. 56-58 (2000)
• [Publications] T.Hamamoto, et al.: "Metamagnetic Transition of CeRh_2Si_2 under High Fields and High Pressures at Various Temperatures"Physica B. 281&282. 64-65 (2000)
• [Publications] A.Yamaguchi, et al.: "Heavy Electron Mass and the Kondo Effect in PrSn_3"Physica B. 281&282. 126-127 (2000)
• [Publications] T.Honma, et al.: "Magnetic, Elastic, Transport and Fermi Surface Properties of a Ferromagnetic Compound UGa_2"Physica B. 281&282. 195-196 (2000)
• [Publications] T.Inoue, et al.: "High-Field Magnetization of UCd_<11>"Physica B. 281&282. 204-205 (2000)
• [Publications] T.D.Matsuda, et al.: "Specific-heat Anomaly of Metamagnetism on PrFe_4P_<12> and UCoAl"Physica B. 282&282. 220-222 (2000)
• [Publications] S.Tsutsui, et al.: "^<238>$U Mossbauer Spectroscopic Study of UPd_2Al_3 and URu_2Si_2"Physica B.. 281&282. 242-243 (2000)
• [Publications] K.Sugiyama, et al.: "Metamagnetism of Uranium Heavy-fermion Compounds UPd_2Al_3, URu2Si_2 and UPt_3"Physica B. 281&282. 244-246 (2000)
• [Publications] T.Nakano, et al.: "Magnetic Properties of the Heavy-fermion Ce(Ru_<1-x>Rh_x)_2Si_2 at the Critical Rh Concentration of the SDW Phase"Physica B. 281&282. 346-348 (2000)
• [Publications] G.Oomi, et al.: "Resistance Anomaly of f-electron Compounds near Pressure-induced Magnetic Instability"Physica B. 281&282. 393-394 (2000)
• [Publications] T.C.Kobayashi, et al.: "Pressure Dependence of Quadrupole Ordering Temperature T_Q in CeB_6"Physica B. 281&282. 553-554 (2000)
• [Publications] S.Takayanagi, et al.: "Pressure Effect on the Cooperative Jahn-teller Transition in PrCu_2"Physica B. 281&282. 583-585 (2000)
• [Publications] T.Takeuchi, et al.: "Thermal Expansion and Magnetostriction of UPd_3"Physica B. 281&282. 602-603 (2000)
• [Publications] Y.Tokiwa: "Quadrupolar Ordering and de Haas-van Alphen Effect in UPd_3"Physica B. 281&282. 604-605 (2000)
• [Publications] N.Kimura: "Fermi Surface Property of UPt_3 Studied by de Haas-van Alphen and Magnetoresistance Experiments"Physica B. 281&282. 710-715 (2000)
• [Publications] T.Ito: "Electronic Band Structure and Fermi Surface of URu_2Si_2 Studied by High-resolution Angle-resolved Photoemission Spectroscopy"Physica B. 281&282. 727-728 (2000)
• [Publications] K.Matsuda: "High-Resolution Resonant Photoemission Study of CeRu_2"Physica B. 281&282. 729-730 (2000)
• [Publications] J.-S.Kang: "Photoemission Study of CeRu_2 and CeCo_2"Physica B. 281&282. 731-733 (2000)
• [Publications] S.Araki: "De Haas-van Alphen Effect in CeNi under Pressure"Physica B. 281&282. 736-737 (2000)
• [Publications] S.Nojiri, et al: "Fermi Surfaces of RIn_3 (R=Tb, Dy, Ho, Er, Tm, Yb and Lu)"Physica B, 281&282(2000), 747-749. 281&282. 747-749 (2000)
• [Publications] T.Ebihara, et al: "Single-crystal Growth and de Haas-van Alphen Effect of YbAl_3"Physica B, 281&282(2000), 754-755. 281&282. 754-755 (2000)
• [Publications] R.Settai, et al: "Cylindrical Fermi Surfaces in Rare-earth and Actinide Compounds"Physica B, 281&282(2000), 758-760. 281&282. 758-760 (2000)
• [Publications] D.Aoki, et al: "Single-crystal Growth by Flux Method and Fermi Surface of Uranium Compounds"Physica B, 281&282(2000), 761-763. 281&282. 761-763 (2000)
• [Publications] E.Yamamoto, et al: "Fermi Surface of UB_4 Studied by the de Haas-van Alphen Oscillation and Magnetoresistance Experiments"Physica B, 281&282(2000), 767-768. 281&282. 767-768 (2000)
• [Publications] P.Wisniewski, et al: "Cylindrical Fermi Surfaces of UAs_2 and UP_2"Physica B, 281&282(2000), 769-770. 281&282. 769-770 (2000)
• [Publications] H.Yamagami, et al: "Orbital Polarization Effect on Electronic Structure and Fermi Surface in Ferromagnetic UGa2"Physica B, 281&282(2000). 281&282. 771-772 (2000)
• [Publications] Y.Haga, et al: "Observation of Heavy Electrons in UPd2Al3"Physica B, 281&282(2000). 281&282. 780-781 (2000)
• [Publications] Y.Kitaoka, et al: "NMR Studies on UPt3"Physica B, 281&282(2000), 878-881. 281&282. 878-881 (2000)
• [Publications] Y.Yoshida, et al: "Fermi Surface and Superconducting Properties in Sr2RuO$_4"Physica B, 281&282(2000), 959-960. 281&282. 959-960 (2000)
• [Publications] W.Higemoto, et al: "Studies of Superconductivity and Magnetism in UPt3 by μ^+SR"Physica B, 281&282(2000). 281&282. 984-986 (2000)
• [Publications] N.Metoki, et al: "Neutron Scattering Studies on Heavy Fermion Superconductors"Physica B, 281&282(2000). 281&282. 987-988 (2000)
• [Publications] K.Tenya, et al: "Magnetization Study in the Superconducting Mixed State of URu2Si2"Physica B, 281&282(2000). 281&282. 991-992 (2000)
• [Publications] Y.Inada, et al: "Anisotropic Superconducting Energy Gap Studied by the dHvA Effect in URu2Si2 and UPd2Al3"Physica B, 281&282(2000). 281&282. 996-997 (2000)
• [Publications] A.Sumiyama, et al: "Josephson Effect of S(Nb)-N(Cu)-S' (Heavy-fermion, Superconductor) Junctions"Physica B, 281&282(2000). 281&282. 1010-1011 (2000)
• [Publications] Y.Inada, et al: "DHvA Oscillation in the Anisotropic Superconductors of UPd2Al3 and URu2Si2"Physica B, 284&288(2000). 284&288. 523-524 (2000)
• [Publications] H.Tsujii, et al: "AC Susceptibility Measurements on Heavy Fermion Compounds CeCu$_6$ and CeNi down to Submillikelvin Temperatures"Physica B, 284&288(2000), 1265-1266. 284&288. 1256-1266 (2000)
• [Publications] D.Takahashi, et al: "Magnetic Behavior of CeRu2Si2 below Millikelvin Temperatures"Physica B, 284&288(2000), 1269-1270. 284&288. 1269-1270 (2000)
• [Publications] T.Namiki, et al: "Hall Effect and Thermoelectric Power in CeCu_<5.9>Au_<0.1> and CeCu_6"Physica B. 281&282. 359-360 (2000)
• [Publications] N.Kimura, et al: "de Haas-van Alphen Effect near the Metamagnetic Transition in UPt_3"Physica B. 284&288. 1279-1280 (2000)
• [Publications] T.Takeuchi, et al: "High-field Magnetization and Thermal Expansion of UPd_3"Physica B. 284&288. 1285-1286 (2000)
• [Publications] Y.Haga, et al: "The Basal-plane Anisotropy in the Paramagnetic State in UPd_2Al_3"Physica B. 284&288. 1289-1290 (2000)
• [Publications] Y.Haga, et al: "de Haas-van Alphen Effect in a Heavy Fermion Superconductor UPd_2Al_3"Physica B. 284&288. 1291-1292 (2000)
• [Publications] Y.Karaki, et al: "Anomalous Temperature Dependence of Resistance in Hyperfine Enhanced Nuclear Antiferromagnet PrIn_3 at mK-temperatures"Physica B. 284&288. 1690-1691 (2000)
• [Publications] H.Inabe, et al: "Magnetic Domain Structure in Hyperfine-enhanced Nuclear Magnet PrCu_6"Physica B. 284&288. 1692-1693 (2000)
• [Publications] H.Amitsuka, et al: "Pressure-Induced Magnetic Phase Transition of the 5f Electron System URu_2Si_2"J.Phys.Soc.Jpn.,. 69. 5-12 (2000)
• [Publications] T.Sakakibara, et al: "Interplay of Orbital and Magnetic Degrees of Freedom in f-Electron Systems : The Cases of PrPb_3 and TmTe"J.Phys.Soc.Jpn.,. 69. 25-32 (2000)
• [Publications] T.Ebihara, et al: "Heavy Fermions in YbAl_3 Studied by the de Haas-van Alphen Effect"J.Phys.Soc.Jpn.,. 69. 895-899 (2000)
• [Publications] Y.Tokiwa, et al: "Fermi Surface Properties of USi_3"J.Phys.Soc.Jpn.,. 69. 1105-1112 (2000)
• [Publications] S.Tsutsui, et al: "^<57>Fe Mossbauer Spectroscopic Study of U_6Fe"J.Phys.Soc.Jpn.,. 69. 1764-1768 (2000)
• [Publications] H.Sakata, et al: "Vortex Lattice and Quasiparticle Density of States in CeRu_2 Studied by Scanning Tunneling Spectroscopy"J.Phys.Soc.Jpn.,. 69. 1970-1973 (2000)
• [Publications] D.Aoki, et al: "Fermi Surface Properties of Enhanced Pauli Paramagnet UAl_3"J.Phys.Soc.Jpn.,. 69. 2609-2614 (2000)
• [Publications] T.Honma, et al: "Magnetic and Fermi Surface Properties of the Ferromagnetic Compound UGa_2"J.Phys.Soc.Jpn.,. 69. 2647-2659 (2000)
• [Publications] A.Sekiyama, et al: "Bulk 4f Electronic States of Ce-Based Heavy Fermion System Probed by High-Resolution Resonance Photomission"J.Phys.Soc.Jpn.,. 69. 2771-2774 (2000)
• [Publications] H.Sugawara, et al: "The Fermi Surface in Filled Skutterudite RFe_4P_<12> (R=La and Nb)"J.Phys.Soc.Jpn.,. 69. 2938-2946 (2000)
• [Publications] R.Settai, et al: "Magnetic and Electrical Properties in a Dense Kondo Compound PrSn_3"J.Phys.Soc.Jpn.,. 69. 3983-3995 (2000)
• [Publications] K.Sakamaki, et al: "Evidence for Superconductivity in Nb_2SC_<0.90> Carbosulfide"D.Aoki, et al. 341. 99-104 (2000)
• [Publications] D.Aoki, et al: "Cylindrical Fermi Surfaces Formed by a Flat Magnetic Brillouin Zone in Uranium Dipnictides"Philo.Mag.B. 80. 1517-1544 (2000)
• [Publications] H.Tsujii, et al: "Magnetic Order in the Heavy Fermion Compound CeCu_6 at mK Temperature"Phys.Rev.Lett.,. 84. 5407-5410 (2000)
• [Publications] A.Sekiyama, et al: "Probing Bulk States of Correlated Electron Systems by High-Resolution Resonance Photoemission"Nature. 403. 396-398 (2000)
• [Publications] 青木大, et al: "反強磁性の小さな磁気ブリルアン・ゾーンが形成するウラン化合物の2次元フェルミ面"固体物理. 35. 355-361 (2000)
• [Publications] T.Tayama, et al: "Antiferro-Quadrupolar Ordering and Multipole Interactions in PrPb_3"J.Phys.Soc.Jpn.,. 70. 248-258 (2000)
• [Publications] P.Wisniewski, et al: "Shubnikov-de Haas Effect Study of Cylindrical Fermi Surface in UP_2"J.Phys.Soc.Jpn.,. 70. 278-283 (2001)
• [Publications] D.Aoki, et al: "Electronic States of the Antiferromagnet UGa_3"J.Phys.Soc.Jpn.,. 70. 538-546 (2001)
• [Publications] Y.Inada, et al: "Magnetoresistance and de Haas-van Alphen Effect in U_3As_4 and U_3P_4"J.Phys.Soc.Jpn.,. 70. 558-568 (2001)
• [Publications] A.Sekiyama: "Bulk 4f electronic states of Ce-Based heavy fermion system probed by high-resolution resonance photoemission"J.Phys.Soc.Jpn.. 69,9. 2771-2774 (2000)
• [Publications] T.Iwasaki: "Bulk and surface electronic structures of CePdX(X=As, Sb) studied by 3d-4f resonance photoemission"Phys.Rev.B. 61,7. 4621-4628 (2000)
• [Publications] S.Yang: "High-resolution Ce 3d-edge resonant photoemission study of CeNi2"Phys.Rev.B. 61. R13329-13332 (2000)
• [Publications] S.Suga: "Angle-resolved, resonance- and inverse photoemission studies of transition metal intercalated TiS2"Molecular Crystals and Liquid Crystals. 341. 9-14 (2000)
• [Publications] A.Sekiyama: "Effect of a crystalline electric field on photoemission spectra of CeB6"Physica B. 281-282. 550-552 (2000)
• [Publications] K.Matsuda: "High resolution resonance photoemission study of CeRu2"Physica B. 281-282. 729-730 (2000)
• [Publications] Y.Saitoh: "Resonance photoemission study of CePtP"Physica B. 281-282. 105-107 (2000)
• [Publications] S.Imada: "Local magnetic states in Nd1-xSrxMnO3"Physica B. 281-282. 498-499 (2000)
• [Publications] S.Suga: "Electronic states of Sm4As3 and Sm4Bi3 studied with photoemission spectroscopy"Physica B. 281-282. 158-160 (2000)