2002 Fiscal Year Annual Research Report

局所磁場測定法による非従来型超伝導体における超伝導状態の研究

Research Project

Project/Area Number	14204034
Research Category	Grant-in-Aid for Scientific Research (A)
Research Institution	The University of Tokyo
Principal Investigator	為ケ井強東京大学, 大学院・工学系研究科, 助教授 (30183073)
Co-Investigator(Kenkyū-buntansha)	徳永将史東京大学, 大学院・工学系研究科, 助手 (50300885)
Keywords	交差格子 / 磁束鎖 / 磁気光学差像法 / 走査型ホール素子顕微鏡 / ポーラス・ボルテックス・マター / 磁束格子融解転移 / CaAlSi / 上部臨海磁場
Research Abstract	異方性の大きな層状超伝導体において、磁場を超伝導面に垂直方向(c軸)から傾いて印加した時に実現される交差格子状態では、c軸方向の磁場によるパンケーキ磁束(PV)と面内磁場によるジョセフソン磁束(JV)が共存する。PVとJVとには、相手の渦電流との相互作用により引力が働く。この結果、交差格子状態では磁束固体相に様々な相が実現される。我々は、磁気光学差像法、走査型ホール素子顕微鏡、または、微小ホール素子による局所磁化測定により、交差格子状態において実現される様々な磁束状態の存在を明らかにした。特に、面内磁場の存在下において、c軸磁場を増加することにより、ロック・イン状態、磁束鎖状態、磁束鎖+格子状態、歪んだ三角格子状態、磁束液体と次々に磁束状態が変化することを示した。また、磁束固体状態において面内磁場を非常に大きくした時に、ある面内磁場において、上記の状態以外の状態が実現することも示した。我々はこの状態を傾いた磁束+格子状態であると考えている。一方、柱状欠陥を導入しピン止めを強めた系において、2種類の磁束がそれぞれ独立の磁束格子融解転移を示すことを磁気光学差像法により示した。この2種類とは、柱状欠陥に強く束縛されたネットワークを形成する磁束と、それらにより囲まれたピン止めの弱い磁束である。このような現象は低密度の柱状欠陥に、それより多い磁束が導入されたときに実現する。新奇超伝導体としてMgB_2と同じAIB_2構造を持つCaAlSiに注目し、フローテイング・ゾーン法による良質の単結晶作製に世界で初めて成功した。CaAlSiも層状構造を反映した異方性を持っており、異方性パラメターは抵抗測定および上部臨界磁場測定から約2.0であることが明らかとなった。しかし、上部臨界磁場の角度依存性は単純な異方的GLモデルに従わず、薄膜における角度依存性の理論であるTinkhamモデルで良くフィットされる。すなわち、超伝導面に平行に磁場が印加されたときに、キンクを示す。バルクの単結晶における測定とは一見矛盾するが、透過電子顕微鏡観察によりこの物質のc軸方向に超格子が存在することを考慮すると、CaAlSiは実質的には2次元面の積層構造として理解されるのかもしれない。

Research Products

(38 results)

All Other

All Publications (38 results)

[Publications] A.K.Pradhan, Z.X.Shi, M.Tokunaga, T.Tamegai, Y.Takano, K.Togano, H.Kito, H.Ihara: "Electrical transport and anisotropic superconducting properties in single crystalline and dense polycrystalline MgB_2"Phys.Rev.B. 64. 21250 (2001)
[Publications] Alexander Grigorenko, Simon Bending, Tsuyoshi Tamegai, Shuuichi Ooi, Mohamed Henini: "A one-dimensional chain state of vortex matter"Nature. 414. 728-731 (2001)
[Publications] A.K.Pradhan, Z.X.Shi, M.Tokunaga, T.Tamegai, Y.Takano, K.Togano, H.Kito, H.Ihara: "Angle-resolved magnetotransport studies in anisotropic MgB_2 single crystals"Phys.Rev.B. 65. 144513 (2002)
[Publications] Z.X.Shi, M.Tokunaga, A.K.Pradhan, T.Tamegai, Y.Takano, K.Togano, H.Kito, H.Ihara: "Lower critical field of MgB2 measured by Hall probe"Physica C. 370. 6-12 (2002)
[Publications] Y.M.Wang, A.Zettl, S.Ooi, T.Tamegai: "Vortex penetration in micron-sized Bi_2Sr_2CaCu_2O_<8+y>"Phys.Rev.B. 65. 184506 (2002)
[Publications] S.Nakamae, C.Capan, K.Behnia, N.E.Hussey, F.Rullier-Albenque, S.Adachi, S.Tajima, C.Urano, Y.Takagi, T.Tamegai, Ch.Marin, E.Walker: "Low-and zero-energy quasiparticle heat transport in high-T_c superconductors"Journal of Physics and Chemistry of Solids. 63. 1065-1068 (2002)
[Publications] M.Yasugaki, K.Itaka, M.Tokunaga, N.Kameda, T.Tamegai: "Magneto-optical observations of crossing-lattices state in Bi_2Sr_2CaCu_20_<8+y>"Phys.Rev.B. 65. 212502 (2002)
[Publications] M.Tokunaga, M.Kobayashi, Y.Tokunaga, T.Tamegai: "Visualization of vortex chains in Bi_2Sr_2CaCu_20_<8+y> by magneto-optical imaging"Phys.Rev.B. 66. 060507 (2002)
[Publications] A.N.Grigorenko, S.J.Bending, A.E.Koshelev, John R.Clem, T.Tameai, S.Ooi: "Visualization of interacting crossing vortex lattices in the presence of quenched disorder"Phys.Rev.Lett.. 89. 217003 (2002)
[Publications] M.Tokunaga, M.Kishi, N.Kameda, K.Itaka, T.Tamegai: "Two-component vortex phase diagram in Bi_2Sr_2CaCu_20_<8+y> under tilted field studied by a micro-Hall probe"Phys.Rev.B. 66. 220501R (2002)
[Publications] M.Yasugaki, M.Tokunaga, N.Kameda, T.Tamegai: "Magneto-optical characterizations of inhomogeneities in Bi_2Sr_2CaCu_20_<8+y> single crystals grown by floating-zone method"Phys.Rev.B. 67. 104504 (2003)
[Publications] M.Tokmnaga, T.Tamegai, Yanina Fasano, F.de la Cruz: "Direct observations of the vortex chain state in Bi_2Sr_2CaCu_20_<8+y> by Bitter decoration"Phys.Rev.B.. (to be published).
[Publications] D.Shaltiel, M.Golosovsky, M.Bezalel, T.Tamegai, E.Walker: "Magnetic fields double frequency, ac and microwave, interaction with the vortex system in highly anisotropic BSCCO"Physica C. 385(to be published). 505-512 (2003)
[Publications] T.Tamegai, M.Tokunaga, M.Kishi, S.Koya, N.Kameda, K.Itaka: "Vortex phase transitions in Bi_2Sr_2CaCu_20_<8+y> in fields nearly parallel and perpendicular to the CuO_2 plane"Physica C. 364-365. 499-503 (2001)
[Publications] M.Kameda, M.Tokunaga, T.Tamegai, M.Konczykowski, S.Okayasu: "Josephson plasma resonance in half-irradiated Bi_2Sr_2CaCu_20_<8+y>"Physica C. 367. 400-403 (2002)
[Publications] N.Avraham, B.Khaykovich, Y.Myasocdov, M.Rappaport, H.Shtrikman, Dima E.Feldman, Eli Zeldov, T.Tamegai, Peter H.Kes, Ming Li, Marcin Konczykowski, C.J.van der Beek: "First-order disorder-driven transition and inverse melting of the vortex lattice"Physica C. 369. 36-44 (2002)
[Publications] A.Soibel, S.S.Banerjee, Y.Myasoedov, M.L.Rappaport, E.Zeldov, S.Ooi, T.Tamegai: "Investigating the vortex melting phenomenon in BSCCO clystals using magneto-optical imaging technique"PRAMANA Journal of Physics. 58. 893-898 (2002)
[Publications] Z.X.Shi, A.K.Pradhan, M.Tokmnaga, K.Yamazaki, T.Tamegai, Y.Takano, K.Toano, H.Kito, H.Ihara: "Magnetic properties and flux pinning in single crystalline and dense polycrystalline MgB_2"Physica C. 378-381. 550-553 (2002)
[Publications] N.Kameda, M.Tokunaga, T.Tamegai, M.Konczykowski: "Mixing of longitudinal and transverse plasma modes in half-irradiated Bi_2Sr_2CaCu_2O_<8+y>"Physica C. 378-381. 546-549 (2002)
[Publications] K.Yamazaki, M.Tokunaga, T.Tamegai, Z.Q.Mao, Y.Maeno, S.Okayasu: "Angular dependence of vortex states in Sr_2RuO_4"Physica C. 378-381. 537-540 (2002)
[Publications] M.Tokunaga, M.Kishi, T.Murata, M.Kobayashi, N.Kameda, T.Tamegai: "Vortex states of Bi_2Sr_2CaCu_2O_<8+y> in tilted-fields studied by a Hall probe"Physica C. 378-381. 475-478 (2002)
[Publications] T.Tamegai, M.Yasugaki, K.Itaka, N.Kameda, M.Tokunaga: "Magneto-optical observations of vortex states under tilted fields in Bi_2Sr_2CaCu_2O_<8+y>"Physica C. 378-381. 416-419 (2002)
[Publications] T.Tokoya, A.Chainani, T.Kiss, S.Shin, K.Hirata, N.Kameda, T.Tamegai, T.Nishio, H.Uwe: "High-resolution photoemission study of Low-T_c superconductors : Phonon induced electronic structures in low-Tc superconductors and comparison with the results of high-Tc cuprates"Physica C. 378-381. 97-101 (2002)
[Publications] T.Murata, M.Tokunaga, T.Tamegai: "Local Permeability Studies of Vortex States in Bi_2Sr_2CaCu_20_<8+y> under Tilted Fields"Physica C. (to be published).
[Publications] T.Tamegai, K.Yamazaki, M.Tokunaga, Zhiqiang Mao, Y.Maeno: "Search for Spontaneous Magnetization in Sr_2RuO_4"Physica C. (to be published).
[Publications] M.Tokmnaga, Y.Tokunaga, T.Tamegai: "Simultaneous Study of Local Magnetization and Resistivity in Phase Separated Manganites"Physica C. (to be published).
[Publications] N.Kameda, M.Tokunaga, T.Tamegai, M.Konczykowski: "Josephson plasma resonance in partially irradiated Bi_2Sr_2CaCu_20_<8+y>"Physica C. (to be published).
[Publications] Z.X.Shi, A.K.Pradhan, M.Tokunaga, T.Tamegai: "Comparative Study on the Anisotropic Properties of MgB_2"Physica C. (to be published).
[Publications] Y.Tokunaga, M.Tokunaga, T.Tamegai: "In-plane Field Induced Stuctural Change of Magnetic Domains in Layered Manganite La_<1.36>Sr_<1.64>Mn_2O_7"Physica C. (to be published).
[Publications] A.K.Ghosh, H.Nakamura, M.Tokunaga, T.Tamegai: "Superconductivity in Y_2PdGe_<3-x>Si_x : interplay between Debye temperature and coupling constant"Physica C. (to be published).
[Publications] T.Tamegai, M.Tokunaga, T.Murata, N.Kameda: "Vortex phase diagram of crossing-lattices state in Bi_2Sr_2CaCu_20_<8+y>"J.Low temp.phys. (to be published).
[Publications] T.Tamegai, Z.X.Shi, A.K.Pradhan, H.Nakamura, A.K.Gohsh, M.Tokunaga, Y.Takano, K.Togano, H.Kito, H.Ihara: "Anisotropic superconducting Properties of MgB_2 and related compounds"J.Low temp.phys. (to be published).
[Publications] M.Tokmnaga, Y.Tokmaga, T.Tamegai, Yanina Fasano: "Observation of vortex chains in Bi_2Sr_2CaCu_20_<8+y>"J.Low temp.phys. (to be published).
[Publications] T.Tamegai, M.Tokunaga, M.Matsui, M.Kobayashi, Y.Tokunaga: "Control of pancake vortices by Josephson vortices in Bi_2Sr_2CaCu_20_<8+y>"Physica C. (to be published).
[Publications] M.Tokunaga, T.Murata, M.Matsui, T.Tamegai: "Crossing vortex lattices states in Bi_2Sr_2CaCu_20_<8+y> with various doing levels"Physica C. (to be published).
[Publications] N.Kameda, M.Tokunaga, T.Tamegai, M.Konzykowski: "Microwave response in Bi_2Sr_2CaCu_20_<8+y> with spatially distributed interlayer phase coherence"Physica C. (to be published).
[Publications] A.K.Ghosh, Y.Hiraoka, N.Kameda, M.Tokunaga, T.Tamegai: "Anisotopic superconductivity in CaAlSi"Physica C. (to be published).
[Publications] T.Tamegai, M.Matsui, Y.Tokunaga, N.Kameda, H.Aoki, M.Tokunaga: "Visualization and Control of Vortex Chains in Bi_2Sr_2CaCu_2O_<8+y>"Int.J.Mod.Phys. (to be published).

2002 Fiscal Year Annual Research Report

局所磁場測定法による非従来型超伝導体における超伝導状態の研究

Principal Investigator

為ケ井 強 東京大学, 大学院・工学系研究科, 助教授 (30183073)

Research Products

[Publications] A.K.Pradhan, Z.X.Shi, M.Tokunaga, T.Tamegai, Y.Takano, K.Togano, H.Kito, H.Ihara: "Electrical transport and anisotropic superconducting properties in single crystalline and dense polycrystalline MgB_2"Phys.Rev.B. 64. 21250 (2001)

[Publications] Alexander Grigorenko, Simon Bending, Tsuyoshi Tamegai, Shuuichi Ooi, Mohamed Henini: "A one-dimensional chain state of vortex matter"Nature. 414. 728-731 (2001)

[Publications] A.K.Pradhan, Z.X.Shi, M.Tokunaga, T.Tamegai, Y.Takano, K.Togano, H.Kito, H.Ihara: "Angle-resolved magnetotransport studies in anisotropic MgB_2 single crystals"Phys.Rev.B. 65. 144513 (2002)

[Publications] Z.X.Shi, M.Tokunaga, A.K.Pradhan, T.Tamegai, Y.Takano, K.Togano, H.Kito, H.Ihara: "Lower critical field of MgB2 measured by Hall probe"Physica C. 370. 6-12 (2002)

[Publications] Y.M.Wang, A.Zettl, S.Ooi, T.Tamegai: "Vortex penetration in micron-sized Bi_2Sr_2CaCu_2O_<8+y>"Phys.Rev.B. 65. 184506 (2002)

[Publications] S.Nakamae, C.Capan, K.Behnia, N.E.Hussey, F.Rullier-Albenque, S.Adachi, S.Tajima, C.Urano, Y.Takagi, T.Tamegai, Ch.Marin, E.Walker: "Low-and zero-energy quasiparticle heat transport in high-T_c superconductors"Journal of Physics and Chemistry of Solids. 63. 1065-1068 (2002)

[Publications] M.Yasugaki, K.Itaka, M.Tokunaga, N.Kameda, T.Tamegai: "Magneto-optical observations of crossing-lattices state in Bi_2Sr_2CaCu_20_<8+y>"Phys.Rev.B. 65. 212502 (2002)

[Publications] M.Tokunaga, M.Kobayashi, Y.Tokunaga, T.Tamegai: "Visualization of vortex chains in Bi_2Sr_2CaCu_20_<8+y> by magneto-optical imaging"Phys.Rev.B. 66. 060507 (2002)

[Publications] A.N.Grigorenko, S.J.Bending, A.E.Koshelev, John R.Clem, T.Tameai, S.Ooi: "Visualization of interacting crossing vortex lattices in the presence of quenched disorder"Phys.Rev.Lett.. 89. 217003 (2002)

[Publications] M.Tokunaga, M.Kishi, N.Kameda, K.Itaka, T.Tamegai: "Two-component vortex phase diagram in Bi_2Sr_2CaCu_20_<8+y> under tilted field studied by a micro-Hall probe"Phys.Rev.B. 66. 220501R (2002)

[Publications] M.Yasugaki, M.Tokunaga, N.Kameda, T.Tamegai: "Magneto-optical characterizations of inhomogeneities in Bi_2Sr_2CaCu_20_<8+y> single crystals grown by floating-zone method"Phys.Rev.B. 67. 104504 (2003)

[Publications] M.Tokmnaga, T.Tamegai, Yanina Fasano, F.de la Cruz: "Direct observations of the vortex chain state in Bi_2Sr_2CaCu_20_<8+y> by Bitter decoration"Phys.Rev.B.. (to be published).

[Publications] D.Shaltiel, M.Golosovsky, M.Bezalel, T.Tamegai, E.Walker: "Magnetic fields double frequency, ac and microwave, interaction with the vortex system in highly anisotropic BSCCO"Physica C. 385(to be published). 505-512 (2003)

[Publications] T.Tamegai, M.Tokunaga, M.Kishi, S.Koya, N.Kameda, K.Itaka: "Vortex phase transitions in Bi_2Sr_2CaCu_20_<8+y> in fields nearly parallel and perpendicular to the CuO_2 plane"Physica C. 364-365. 499-503 (2001)

[Publications] M.Kameda, M.Tokunaga, T.Tamegai, M.Konczykowski, S.Okayasu: "Josephson plasma resonance in half-irradiated Bi_2Sr_2CaCu_20_<8+y>"Physica C. 367. 400-403 (2002)

[Publications] N.Avraham, B.Khaykovich, Y.Myasocdov, M.Rappaport, H.Shtrikman, Dima E.Feldman, Eli Zeldov, T.Tamegai, Peter H.Kes, Ming Li, Marcin Konczykowski, C.J.van der Beek: "First-order disorder-driven transition and inverse melting of the vortex lattice"Physica C. 369. 36-44 (2002)

[Publications] A.Soibel, S.S.Banerjee, Y.Myasoedov, M.L.Rappaport, E.Zeldov, S.Ooi, T.Tamegai: "Investigating the vortex melting phenomenon in BSCCO clystals using magneto-optical imaging technique"PRAMANA Journal of Physics. 58. 893-898 (2002)

[Publications] Z.X.Shi, A.K.Pradhan, M.Tokmnaga, K.Yamazaki, T.Tamegai, Y.Takano, K.Toano, H.Kito, H.Ihara: "Magnetic properties and flux pinning in single crystalline and dense polycrystalline MgB_2"Physica C. 378-381. 550-553 (2002)

[Publications] N.Kameda, M.Tokunaga, T.Tamegai, M.Konczykowski: "Mixing of longitudinal and transverse plasma modes in half-irradiated Bi_2Sr_2CaCu_2O_<8+y>"Physica C. 378-381. 546-549 (2002)

[Publications] K.Yamazaki, M.Tokunaga, T.Tamegai, Z.Q.Mao, Y.Maeno, S.Okayasu: "Angular dependence of vortex states in Sr_2RuO_4"Physica C. 378-381. 537-540 (2002)

[Publications] M.Tokunaga, M.Kishi, T.Murata, M.Kobayashi, N.Kameda, T.Tamegai: "Vortex states of Bi_2Sr_2CaCu_2O_<8+y> in tilted-fields studied by a Hall probe"Physica C. 378-381. 475-478 (2002)

[Publications] T.Tamegai, M.Yasugaki, K.Itaka, N.Kameda, M.Tokunaga: "Magneto-optical observations of vortex states under tilted fields in Bi_2Sr_2CaCu_2O_<8+y>"Physica C. 378-381. 416-419 (2002)

[Publications] T.Murata, M.Tokunaga, T.Tamegai: "Local Permeability Studies of Vortex States in Bi_2Sr_2CaCu_20_<8+y> under Tilted Fields"Physica C. (to be published).

[Publications] T.Tamegai, K.Yamazaki, M.Tokunaga, Zhiqiang Mao, Y.Maeno: "Search for Spontaneous Magnetization in Sr_2RuO_4"Physica C. (to be published).

[Publications] M.Tokmnaga, Y.Tokunaga, T.Tamegai: "Simultaneous Study of Local Magnetization and Resistivity in Phase Separated Manganites"Physica C. (to be published).

[Publications] N.Kameda, M.Tokunaga, T.Tamegai, M.Konczykowski: "Josephson plasma resonance in partially irradiated Bi_2Sr_2CaCu_20_<8+y>"Physica C. (to be published).

[Publications] Z.X.Shi, A.K.Pradhan, M.Tokunaga, T.Tamegai: "Comparative Study on the Anisotropic Properties of MgB_2"Physica C. (to be published).

[Publications] Y.Tokunaga, M.Tokunaga, T.Tamegai: "In-plane Field Induced Stuctural Change of Magnetic Domains in Layered Manganite La_<1.36>Sr_<1.64>Mn_2O_7"Physica C. (to be published).

[Publications] A.K.Ghosh, H.Nakamura, M.Tokunaga, T.Tamegai: "Superconductivity in Y_2PdGe_<3-x>Si_x : interplay between Debye temperature and coupling constant"Physica C. (to be published).

[Publications] T.Tamegai, M.Tokunaga, T.Murata, N.Kameda: "Vortex phase diagram of crossing-lattices state in Bi_2Sr_2CaCu_20_<8+y>"J.Low temp.phys. (to be published).

[Publications] T.Tamegai, Z.X.Shi, A.K.Pradhan, H.Nakamura, A.K.Gohsh, M.Tokunaga, Y.Takano, K.Togano, H.Kito, H.Ihara: "Anisotropic superconducting Properties of MgB_2 and related compounds"J.Low temp.phys. (to be published).

[Publications] M.Tokmnaga, Y.Tokmaga, T.Tamegai, Yanina Fasano: "Observation of vortex chains in Bi_2Sr_2CaCu_20_<8+y>"J.Low temp.phys. (to be published).

[Publications] T.Tamegai, M.Tokunaga, M.Matsui, M.Kobayashi, Y.Tokunaga: "Control of pancake vortices by Josephson vortices in Bi_2Sr_2CaCu_20_<8+y>"Physica C. (to be published).

[Publications] M.Tokunaga, T.Murata, M.Matsui, T.Tamegai: "Crossing vortex lattices states in Bi_2Sr_2CaCu_20_<8+y> with various doing levels"Physica C. (to be published).

[Publications] N.Kameda, M.Tokunaga, T.Tamegai, M.Konzykowski: "Microwave response in Bi_2Sr_2CaCu_20_<8+y> with spatially distributed interlayer phase coherence"Physica C. (to be published).

[Publications] A.K.Ghosh, Y.Hiraoka, N.Kameda, M.Tokunaga, T.Tamegai: "Anisotopic superconductivity in CaAlSi"Physica C. (to be published).

[Publications] T.Tamegai, M.Matsui, Y.Tokunaga, N.Kameda, H.Aoki, M.Tokunaga: "Visualization and Control of Vortex Chains in Bi_2Sr_2CaCu_2O_<8+y>"Int.J.Mod.Phys. (to be published).

為ケ井強東京大学, 大学院・工学系研究科, 助教授 (30183073)