2002 Fiscal Year Annual Research Report

遷移金属酸化物における電荷・軌道ダイナミックスのスペクトロスコピー

Research Project

Project/Area Number	12046220
Research Institution	The University of Tokyo
Principal Investigator	内田慎一東京大学, 大学院・理学系研究科, 教授 (10114399)
Co-Investigator(Kenkyū-buntansha)	松田祐司東京大学, 物性研究所, 助教授 (50199816) 藤森淳東京大学, 大学院・新領域創成科学研究科, 教授 (10209108)
Keywords	銅酸化物高温超伝導体 / 有機超伝導体 / 重い電子系 / 角度分解光電子分光 / STM / 熱伝導度 / 準粒子スペクトル / 超伝導対称性
Research Abstract	銅酸化物を中心に遷移金属酸化物、有機物、重い電子系物質を対象に、光電子分光、STS/STM、遠赤外分光、マイクロ波、NMR、電子輸送現象等様々なスペクトルスコピー手法を用いて、その電子状態、準粒子ダイナミックス、超伝導特性を探求した。銅酸化物高温超伝導体においては、その電子状態の実空間及び運動量空間での不均一性を明らかにした。アンダードープ物質において、超伝導相と非超伝導相とにナノメートルスケールで相分離していることをSTS/STMで発見したが、この不均一性により散乱された準粒子が量子力学干渉によりつくる局所状態密度の濃淡を観測する事に成功した。光電子分光では微量に正孔をドープしたBi系、Y系の高温超伝導体と、La系との違いが、第二近接銅原子間の移動積分t'の大きさの違いに起因する事を示した。擬ギャップの大きさ、ストライプの不安定性などの物性がt'により支配されていることを示唆するものである。悌子型銅酸化物について、その超伝導相を含めて、ほぼ完全な電子相図を完成させるとともに、相図上の大部分の領域を占める絶縁体相の成因が電荷秩序であることを、その集団励起モードの観測により示した。熱伝導度を極低温で磁場を試料に対し様々な角度で変化させることにより有機超伝導体κ-(BEDT-TTF)_2Cu(NCS)_2、ボロカーバイド超伝導体YNi_2B_2C、スクッテルダイト重い電子超伝導体PrOs_4Sb_<12>の超伝導ギャップの形状を決定した。その結果κ-(BEDT-TTF)_2Cu(NCS)_2では対称性はd_<xy>に近いこと、YNi_2B_2Cではポイントノードを持っていることPrOs_4Sb_<12>では超伝導相で2つの異なる対称性を持つことを示した。

Research Products

(39 results)

All Other

All Publications (39 results)

[Publications] M.Z.Hasan: "Momentum-Resolved Charge Excitations in a Prototype One-Dimesional Mott Insulator"Phys.Rev.Lett.. 88. 177403 (2002)
[Publications] S.Arumugam: "Competition of Static Stripe and Superconducting Phases in La_<1.48>Nd_<0.4>Sr_<0.12>CuO_4 Controlled by Pressure"Phys.Rev.Lett.. 88. 247001 (2002)
[Publications] Y.Wang: "High Field Phase Diagram of Cuprate Derived from the Nernst Effect"Phys.Rev.Lett.. 88. 257003 (2002)
[Publications] N.Motoyama: "Electronic phase diagram of a hole-doped two-leg ladder system, Sr_<14-x>Ca_xCu_<24>O_<41>"Europhys.Lett. 58. 758-763 (2002)
[Publications] K.M.Kojima: "New Josephson Plasma Modes in Underdoped YBa_2Cu_3O_<6.6> Induced by a Parallel Magnetic Field"Phys.Rev.Lett.. 89. 174516 (2002)
[Publications] C.Kim: "Anomalous temperature dependence in the photoemission spectral function of cuprates"Phys.Rev.B. 65. 174516 (2002)
[Publications] G.Blumberg: "Sliding Density Wave in Sr_<14>Cu_<24>O_<14> Ladder Compounds"Science. 297. 504-587 (2002)
[Publications] J.E.Hoffmah: "Imaging Quasiparticle Interference in Bi_2Sr_2CaCu_2O_<8+σ>"Science. 297. 1248-1151 (2002)
[Publications] Y.Wang: "Dependence of Upper Critical Field and Pairing Strength on Doping in Cuprates"Science. 299. 86-89 (2002)
[Publications] H.Ueda: "Copper Pyrites CuS_2 and CuSe_2 as Anion Conductors"Phys.Rev.B. 65. 155104 (2002)
[Publications] K.Okazaki: "Temperature-dependent Electronic Structure of VO_2"J.Phys.Soc.Jpn.. 71. 822 (2002)
[Publications] T.Mizokawa: "Observation of Single Particle Spectral Function of a Tomonaga-Luttinger Liquid : Angle-Resolved Photoemission Study of Zn-Doped PrBa_2Cu_4O_8"Phys.Rev.B. 65. 193101 (2002)
[Publications] S.-i.Fujimori: "Angle-Resolved Photoemission Study of Halogen-Bridged MX-Chain Compound[Ni(chxn)_2Br]Br_2 : Spin-Charge Separation in Hybridized d-p Chains"Phys.Rev.Lett.. 88. 247601 (2002)
[Publications] T.Yoshida: "Photoemission Spectral Weight Transfer and Mass Renormalization in the Fermi-Liquid System La_<1-x>Sr_xTiO_<3+y/2>"Europhys.Lett.. 59. 258 (2002)
[Publications] J.Matsuno: "Chemical Potential Shift in La_<1-x>Sr_xMnO_3 : Photoemission Test of the Phase Separation Scenario"Europhys.Lett.. 59. 252 (2002)
[Publications] K.Kobayashi: "Disorder Effects in the Bipolaron System Ti_4O_7 Studied by Photoemission Spectroscopy"Europhys.Lett. 56. 868 (2002)
[Publications] J.D.Lee: "On the AREPS Intensities in a System with the Bilayer Coupling : Beyound the Transition-Matrix Elelemts Effects"Phys.Rev.B. 66. 144509 (2002)
[Publications] J.Matsuno: "Different Routes to Charge Disproportionation in Perovskites-Type Fe Oxides"Phys.Rev.B. 66. 193103 (2002)
[Publications] K.Okazaki: "Crossover in the Nature of the Metallic Phases in the Perovskite-Type RNiO_3"Phys.Rev.B. 67. 073101 (2003)
[Publications] A.Lanzara: "Coupling of Quasiparticles to Phonons in High Temperature Superconductors"J.Electron Spectrosc.Relat.Phenom. 127. 37 (2002)
[Publications] K.Okazaki: "Temperature-Dependent Electronic Structure of Nd_<1-x>Sm_xNiO_3, in Proceedings of Todai International Symposium ISSP 2001, Correlated Electrons"J.Phys.Chem.Solids.. 63. 975 (2002)
[Publications] A.Fujimori: "Core-Level Photoemission Measurements of the Chemical Potential Shift as a Probe of Correlated Electron Systems"J.Electron Spectrosc.Relat.Phenom.. 124. 127 (2002)
[Publications] T.Yoshida: "ARPES study of lightly-doped La_<2-x>Sr_xCuO_4"Physica C. (印刷中).
[Publications] J.Okamoto: "Electronic Structure of the Pyrochlore-Type Ru Oxides through the Metal-Insulator Transition"Acta Phys.Polonica. (印刷中).
[Publications] K.Kuinagai: "Charged Vortices in High Temperature Superconductors Probed by NMR"Phys.Rev.B. 63. 144502-1-144502-6 (2001)
[Publications] K.Izawa: "Low Energy Quasiparticle Excitation In the Vortex State of Borocarbide Superconductor YNi_2 B_2C"Phys.Rev.Lett.. 86. 1327-1330 (2001)
[Publications] K.Izawa: "Superconducting Gap Structure of Spin-Triplet Superconductor Sr_2RuO_4 Studied by Thermal Conductivity"Phys.Rev.Lett.. 86. 2653-1-2653-4 (2001)
[Publications] T.Shibauchi: "Comment on "Millimeter-Wave Magneto-optical Determination of the Anisotropy of the Superconducting Order Parameter in the Molecular Superconductor kappa-(BEDT-TTF)_2Cu(NCS)_2""Phys.Rev.Lett.. 86. 3452-1-3452-4 (2001)
[Publications] L.N.Bulaevskii: "Critical Current and Josephson Plasma Resonancein the Vortex Glass Phase of Bi{_2}Sr{_2}CaCu{_2}O{_8delta}"Phys.Rev.B.. 63. 140503-1-140503-6 (2001)
[Publications] K.Izawa: "Angular position of nodes in the superconducting gap of quasi-2D heavy-fermion superconductor CeCoIn_5"Phys.Rev.Lett.. 87. 057002-1-057002-4 (2001)
[Publications] Yu.I.Latyshev: "Shapiro Step Response in the Coherent Josephson Flux Flow State of Bi_2Sr_2CaCu_2O{_8+delta}"Phys.Rev.Lett.. 87. 247007-1-247007-4 (2001)
[Publications] K.Izawa: "Superconducting Gap Structure of kappa (BEDT-TTF)_2Cu(NCS)_2 Probed by Thermal Conductivity Tensor"Phys.Rev.Lett.. 88. 027002-1-027002-4 (2002)
[Publications] K.Kakuyanagi: "Quasiparticle excitation in and around the vortex core of underdoped YBa_2Cu_4O_8 studied by site-selective NMR"Phys.Rev.B. 65. 060503-1-060503-6 (2002)
[Publications] K.Kuroki: "d{x^2-y^2}-versus d{xy}-like Pairings in Organic Superconductors kappa-(BEDT-TTF)_2X"Phys.Rev.B. 65. 100516-1-100516-6 (2002)
[Publications] Y.Matsuda: "Free flux flow resistivity in a strongly overdoped high-T_ccuprate The purely viscous motion of vortices in a semiclassical d-wave superconductor"Phys.Rev.B. 66. 014527-1-014527-8 (2002)
[Publications] K.Izawa: "Gap function with point nodes in borocarbide superconductor YNi_2 B_2C"Phys.Rev.Lett.. 89. 137006-1-137006-4 (2002)
[Publications] K.Izawa: "Multiple Superconducting Phases in New Heavy Fermion Superconductor PrOs_4Sb_<{12}>"Phys.Rev.Lett.. (印刷中).
[Publications] S.Colson: "Vortex fluctuations in underdoped Bi_2Sr_2CaCu_2O{_8+delta} crystals"Phys.Rev.Lett.. (印刷中).
[Publications] K.Kakuyanagi: "Antiferromagnetic ordering and disappearance of pseudogap within the vortex core of TI_2Ba_2CuO{6+delta}"Phys.Rev.Lett.. (印刷中).

2002 Fiscal Year Annual Research Report

遷移金属酸化物における電荷・軌道ダイナミックスのスペクトロスコピー

Principal Investigator

内田 慎一 東京大学, 大学院・理学系研究科, 教授 (10114399)

Research Products

[Publications] M.Z.Hasan: "Momentum-Resolved Charge Excitations in a Prototype One-Dimesional Mott Insulator"Phys.Rev.Lett.. 88. 177403 (2002)

[Publications] S.Arumugam: "Competition of Static Stripe and Superconducting Phases in La_<1.48>Nd_<0.4>Sr_<0.12>CuO_4 Controlled by Pressure"Phys.Rev.Lett.. 88. 247001 (2002)

[Publications] Y.Wang: "High Field Phase Diagram of Cuprate Derived from the Nernst Effect"Phys.Rev.Lett.. 88. 257003 (2002)

[Publications] N.Motoyama: "Electronic phase diagram of a hole-doped two-leg ladder system, Sr_<14-x>Ca_xCu_<24>O_<41>"Europhys.Lett. 58. 758-763 (2002)

[Publications] K.M.Kojima: "New Josephson Plasma Modes in Underdoped YBa_2Cu_3O_<6.6> Induced by a Parallel Magnetic Field"Phys.Rev.Lett.. 89. 174516 (2002)

[Publications] C.Kim: "Anomalous temperature dependence in the photoemission spectral function of cuprates"Phys.Rev.B. 65. 174516 (2002)

[Publications] G.Blumberg: "Sliding Density Wave in Sr_<14>Cu_<24>O_<14> Ladder Compounds"Science. 297. 504-587 (2002)

[Publications] J.E.Hoffmah: "Imaging Quasiparticle Interference in Bi_2Sr_2CaCu_2O_<8+σ>"Science. 297. 1248-1151 (2002)

[Publications] Y.Wang: "Dependence of Upper Critical Field and Pairing Strength on Doping in Cuprates"Science. 299. 86-89 (2002)

[Publications] H.Ueda: "Copper Pyrites CuS_2 and CuSe_2 as Anion Conductors"Phys.Rev.B. 65. 155104 (2002)

[Publications] K.Okazaki: "Temperature-dependent Electronic Structure of VO_2"J.Phys.Soc.Jpn.. 71. 822 (2002)

[Publications] T.Mizokawa: "Observation of Single Particle Spectral Function of a Tomonaga-Luttinger Liquid : Angle-Resolved Photoemission Study of Zn-Doped PrBa_2Cu_4O_8"Phys.Rev.B. 65. 193101 (2002)

[Publications] S.-i.Fujimori: "Angle-Resolved Photoemission Study of Halogen-Bridged MX-Chain Compound[Ni(chxn)_2Br]Br_2 : Spin-Charge Separation in Hybridized d-p Chains"Phys.Rev.Lett.. 88. 247601 (2002)

[Publications] T.Yoshida: "Photoemission Spectral Weight Transfer and Mass Renormalization in the Fermi-Liquid System La_<1-x>Sr_xTiO_<3+y/2>"Europhys.Lett.. 59. 258 (2002)

[Publications] J.Matsuno: "Chemical Potential Shift in La_<1-x>Sr_xMnO_3 : Photoemission Test of the Phase Separation Scenario"Europhys.Lett.. 59. 252 (2002)

[Publications] K.Kobayashi: "Disorder Effects in the Bipolaron System Ti_4O_7 Studied by Photoemission Spectroscopy"Europhys.Lett. 56. 868 (2002)

[Publications] J.D.Lee: "On the AREPS Intensities in a System with the Bilayer Coupling : Beyound the Transition-Matrix Elelemts Effects"Phys.Rev.B. 66. 144509 (2002)

[Publications] J.Matsuno: "Different Routes to Charge Disproportionation in Perovskites-Type Fe Oxides"Phys.Rev.B. 66. 193103 (2002)

[Publications] K.Okazaki: "Crossover in the Nature of the Metallic Phases in the Perovskite-Type RNiO_3"Phys.Rev.B. 67. 073101 (2003)

[Publications] A.Lanzara: "Coupling of Quasiparticles to Phonons in High Temperature Superconductors"J.Electron Spectrosc.Relat.Phenom. 127. 37 (2002)

[Publications] K.Okazaki: "Temperature-Dependent Electronic Structure of Nd_<1-x>Sm_xNiO_3, in Proceedings of Todai International Symposium ISSP 2001, Correlated Electrons"J.Phys.Chem.Solids.. 63. 975 (2002)

[Publications] A.Fujimori: "Core-Level Photoemission Measurements of the Chemical Potential Shift as a Probe of Correlated Electron Systems"J.Electron Spectrosc.Relat.Phenom.. 124. 127 (2002)

[Publications] T.Yoshida: "ARPES study of lightly-doped La_<2-x>Sr_xCuO_4"Physica C. (印刷中).

[Publications] J.Okamoto: "Electronic Structure of the Pyrochlore-Type Ru Oxides through the Metal-Insulator Transition"Acta Phys.Polonica. (印刷中).

[Publications] K.Kuinagai: "Charged Vortices in High Temperature Superconductors Probed by NMR"Phys.Rev.B. 63. 144502-1-144502-6 (2001)

[Publications] K.Izawa: "Low Energy Quasiparticle Excitation In the Vortex State of Borocarbide Superconductor YNi_2 B_2C"Phys.Rev.Lett.. 86. 1327-1330 (2001)

[Publications] K.Izawa: "Superconducting Gap Structure of Spin-Triplet Superconductor Sr_2RuO_4 Studied by Thermal Conductivity"Phys.Rev.Lett.. 86. 2653-1-2653-4 (2001)

[Publications] T.Shibauchi: "Comment on "Millimeter-Wave Magneto-optical Determination of the Anisotropy of the Superconducting Order Parameter in the Molecular Superconductor kappa-(BEDT-TTF)_2Cu(NCS)_2""Phys.Rev.Lett.. 86. 3452-1-3452-4 (2001)

[Publications] L.N.Bulaevskii: "Critical Current and Josephson Plasma Resonancein the Vortex Glass Phase of Bi{_2}Sr{_2}CaCu{_2}O{_8delta}"Phys.Rev.B.. 63. 140503-1-140503-6 (2001)

[Publications] K.Izawa: "Angular position of nodes in the superconducting gap of quasi-2D heavy-fermion superconductor CeCoIn_5"Phys.Rev.Lett.. 87. 057002-1-057002-4 (2001)

[Publications] Yu.I.Latyshev: "Shapiro Step Response in the Coherent Josephson Flux Flow State of Bi_2Sr_2CaCu_2O{_8+delta}"Phys.Rev.Lett.. 87. 247007-1-247007-4 (2001)

[Publications] K.Izawa: "Superconducting Gap Structure of kappa (BEDT-TTF)_2Cu(NCS)_2 Probed by Thermal Conductivity Tensor"Phys.Rev.Lett.. 88. 027002-1-027002-4 (2002)

[Publications] K.Kakuyanagi: "Quasiparticle excitation in and around the vortex core of underdoped YBa_2Cu_4O_8 studied by site-selective NMR"Phys.Rev.B. 65. 060503-1-060503-6 (2002)

[Publications] K.Kuroki: "d{x^2-y^2}-versus d{xy}-like Pairings in Organic Superconductors kappa-(BEDT-TTF)_2X"Phys.Rev.B. 65. 100516-1-100516-6 (2002)

[Publications] Y.Matsuda: "Free flux flow resistivity in a strongly overdoped high-T_ccuprate The purely viscous motion of vortices in a semiclassical d-wave superconductor"Phys.Rev.B. 66. 014527-1-014527-8 (2002)

[Publications] K.Izawa: "Gap function with point nodes in borocarbide superconductor YNi_2 B_2C"Phys.Rev.Lett.. 89. 137006-1-137006-4 (2002)

[Publications] K.Izawa: "Multiple Superconducting Phases in New Heavy Fermion Superconductor PrOs_4Sb_<{12}>"Phys.Rev.Lett.. (印刷中).

[Publications] S.Colson: "Vortex fluctuations in underdoped Bi_2Sr_2CaCu_2O{_8+delta} crystals"Phys.Rev.Lett.. (印刷中).

[Publications] K.Kakuyanagi: "Antiferromagnetic ordering and disappearance of pseudogap within the vortex core of TI_2Ba_2CuO{6+delta}"Phys.Rev.Lett.. (印刷中).

内田慎一東京大学, 大学院・理学系研究科, 教授 (10114399)