1998 Fiscal Year Annual Research Report

磁気-光-電子・量子機能基礎研究

Research Project

Project/Area Number	10142101
Research Institution	Hokkaido University
Principal Investigator	栗城真也北海道大学, 電子科学研究所, 教授 (30002108)
Co-Investigator(Kenkyū-buntansha)	木須隆暢九州大学, システム情報科学研究科, 助教授 (00221911) 斗内政吉大阪大学, 超伝導エレクトロニクス研究センター, 助教授 (40207593) 菅原昌敬横浜国立大学, 工学部, 教授 (40017900) 大矢銀一郎宇都宮大学, 工学研究科, 教授 (00006280) 大嶋重利山形大学, 工学部, 教授 (40124557)
Keywords	ボルテックス / 高温超伝導 / SQUID / 固有ジョセフソン接合 / 磁束ピニング
Research Abstract	ボルテックスの検出と可視化の研究に関し、SQUIDを用いて超伝導薄膜デバイスのボルテックスノイズを直接検出する方法を開発し、エピタキシャル成長したNb薄膜不均質ブリッジ(VTB)と多結晶Nb薄膜VTBのノイズ特性を計測し、それぞれブリッジ内へのボルテックスの侵入とブリッジ内でトラップされたボルテックスの解放がダイナミクスを決定していることを明らかにした。また、ビッター法により高温超伝導体のY123,Bi2212単結晶のボルテックスとそれらのパターンを観察し、超伝導体のマイスナー状態からボルテックスが侵入する様子や試料に電流を通電したときのボルテックス侵入過程を明らかにした。さらに、フェムト秒光パルスを用いて高温超伝導体中の超伝導電流を高速変調することで放射されるテラヘルツ電磁波のイメージングから、超伝導電流分布が観測できることを見出した。この手法を用いて、高温超伝導体中に侵入したボルテックスを非破壊・非接触で可視化することに成功した。ボルテックス運動と量子効果の解析に関する研究では、Bi2212単結晶の固有ジョセフソン接合超格子メサにおいて、磁界印加によりジョセフソン・ボルテックス運動に起因するフィスケ・ステップおよびボルテックス・フロー・ステップの観測に成功し、ボルテックスが約10^6m/sの高速で運動することを見出した。また、局在性を導入したLSCO薄膜で、室温でも観測できる新しい巨視的量子効果が発現することを明らかにし、負誘電特性、CO_2レーザ波との干渉および誘電的干渉パターンの観測に成功した。さらに、YBCO高温超伝導薄膜の磁束ピン止め力と、その統計分布、異方性を定量的に評価する手法を確立し、ボルテックスの熱運動に伴うデピニング現象について数値シミュレーションならびに一体近似理論を用いて調べ、そのダイナミクスと統計的特性を明らかした。

Research Products
(20 results)

All Other

All Publications (20 results)

[Publications] K.Yokosawa, E.Maruyama,他: "Single-layer high-T_csuperconducting quantum interference device magnetometer with double-pickup-coil configuration" Jpn.J.Appl.Phys.37,Pt.1(8). 4362-4366 (1998)
[Publications] E.Maruyama, S.Kuriki 他: "Flux coupling in the direct-coupled high-T_csuperconducting quantum interference devices" Jpn.J.Appl.Phys.37,Pt.2(6B). 722-724 (1998)
[Publications] E.Maruyama, S.Kuriki, Y.Kurisu, 他: "Analytical approach to caluclate the flux dependent current-voltage characteristics of dc superconducting quantum interference devices" J.Appl.Phys.83(11). 6166-6171 (1998)
[Publications] K.D.Develos, M.Kusunoki 他: "Studies on the surface morphology and orientation of CeO_2 films deposited by pulsed laser ablation" Jp.J.Appl.Phys.37. 6161-6169 (1998)
[Publications] S.Oshima, T.Koseki 他: "Observation of vortex movements in a Bi2212 single crystal under application of a transport current by means of a bitter pattern technique" Jpn.J.Appl.Phys.37. 375-378 (1998)
[Publications] A.Irie, Y.Hirai and G.Oya: "Fiske and flux-flow modes of the intrinsic josephson junctions in Bi_2Sr_2CaCu_2O_ymesas" Appl.Phys.Lett.72. 2159-2161 (1998)
[Publications] M.Sugahara, H.F.Lu, H.Q.Yin 他: "Anomalous hysteretic dielectric polarization in c-axis-oriented La_<2-x>Sr_xCuO_4 film" Advances in Superconductivity (Springer-Verlag). Vol.1. 115-118 (1998)
[Publications] T.Kiss, T.Nakamura, K.Hasegawa 他: "Transport characteristics in high Tc superconductors" Proc.of MT15 (Science Press). Part.2. 1052-1055 (1998)
[Publications] H.Okamoto, F.Irie, T.Kiss 他: "Characterization of Ag/Bi-2223 tapes in wide range of temperature and magnetic field" Proc.of MT15 (Science Press). Part2. 1071-1074 (1998)
[Publications] V.S.Vysotsly, T.Kiss, M.Takeo, 他: "The stability characteristics of Bi-based high temperature superconducting coil" Proc.of MT15 (Science Press). Part2. 1056-1059 (1998)
[Publications] T.Nakamura, T.Kiss, Y.Hanayama, 他: "Transport properties in YBa_2Cu_3O_<7-y> superconducting thin films over wode range of electric field" Advances in Superconductivity (Springer-Verlag). 10. 581-584 (1998)
[Publications] Yu.A.Ilyin, T.Nakamura 他: "Critical current distribution along the Bi-2212 high temperature superconducting coil" Advances in Superconductivity (Springer-Verlag). 10. 799-802 (1998)
[Publications] T.Sueyoshi, N.Ishikawa, A.Iwase 他: "Transport characteristics near the glass-liquid transition temperature before and after heavy-iron irradiation in a YBa_2Cu_3O_<7-y> thin film" Physica. C309. 79-88 (1998)
[Publications] T.Kiss, T.Nakamura, K.Hasegawa 他: "Nonlinear resistance in high Tc superconductors as a function of bias current density, temperature and magnetic field" ICEC (IOP Publishing). 17. 427-430 (1998)
[Publications] V.S.Vysotsky, T.Kiss, Yu.A.Ilyin 他: "Heat and quechpropergation in HTSC coils with bobbins from different materials (Part1, Experiment)" ICEC (IOP Publishing). 17. 583-586 (1998)
[Publications] M.Tanouchi, S.Shikii, M.Yamashita 他: "Visualization of optically controlled magnetic flux in YBa_2Cu_3O_<7-d> thin film loop by terahertz radiation imaging" Jpn.J.Appl.Phys.37.Pt.2(11A). 1301-1303 (1998)
[Publications] S.Shikii, T.Kondo, M.Yamashita 他: "Observation of supercurrent distribution in YBa_2Cu_3O_<7-d> thin films using THz radiation excited with femtosecond laser pulses" Appl.Phys.Lett.74(3)(To be published). (1999)
[Publications] O.Morikawa, M.Tonouchi, M.Tani 他: "Sub-THz emission properties of photoconductive antennas excited with multimode laser diode" J.Appl.Phys.Part 1.38(3)(To be published). (1999)
[Publications] K.Develos, M.Kusunoki 他: "Studies on Surface Morphology and Orientation of CeO_2 Films Deposited by Pulsed Laser Ablation" Jpn.J.Appl.Phys.37. 6161-6169 (1998)
[Publications] M.Sugahara, S.Mitani, H.F.Lu 他: "Theory and experimental evidence for pair FQHE state caused by zero-point harmonic oscillation in block-layer potential" Summetry and Pairing in Superconductors (Kluwer). 287-300 (1999)

1998 Fiscal Year Annual Research Report

磁気-光-電子・量子機能基礎研究

Principal Investigator

栗城 真也 北海道大学, 電子科学研究所, 教授 (30002108)

Research Products

[Publications] K.Yokosawa, E.Maruyama,他: "Single-layer high-T_csuperconducting quantum interference device magnetometer with double-pickup-coil configuration" Jpn.J.Appl.Phys.37,Pt.1(8). 4362-4366 (1998)

[Publications] E.Maruyama, S.Kuriki 他: "Flux coupling in the direct-coupled high-T_csuperconducting quantum interference devices" Jpn.J.Appl.Phys.37,Pt.2(6B). 722-724 (1998)

[Publications] E.Maruyama, S.Kuriki, Y.Kurisu, 他: "Analytical approach to caluclate the flux dependent current-voltage characteristics of dc superconducting quantum interference devices" J.Appl.Phys.83(11). 6166-6171 (1998)

[Publications] K.D.Develos, M.Kusunoki 他: "Studies on the surface morphology and orientation of CeO_2 films deposited by pulsed laser ablation" Jp.J.Appl.Phys.37. 6161-6169 (1998)

[Publications] S.Oshima, T.Koseki 他: "Observation of vortex movements in a Bi2212 single crystal under application of a transport current by means of a bitter pattern technique" Jpn.J.Appl.Phys.37. 375-378 (1998)

[Publications] A.Irie, Y.Hirai and G.Oya: "Fiske and flux-flow modes of the intrinsic josephson junctions in Bi_2Sr_2CaCu_2O_ymesas" Appl.Phys.Lett.72. 2159-2161 (1998)

[Publications] M.Sugahara, H.F.Lu, H.Q.Yin 他: "Anomalous hysteretic dielectric polarization in c-axis-oriented La_<2-x>Sr_xCuO_4 film" Advances in Superconductivity (Springer-Verlag). Vol.1. 115-118 (1998)

[Publications] T.Kiss, T.Nakamura, K.Hasegawa 他: "Transport characteristics in high Tc superconductors" Proc.of MT15 (Science Press). Part.2. 1052-1055 (1998)

[Publications] H.Okamoto, F.Irie, T.Kiss 他: "Characterization of Ag/Bi-2223 tapes in wide range of temperature and magnetic field" Proc.of MT15 (Science Press). Part2. 1071-1074 (1998)

[Publications] V.S.Vysotsly, T.Kiss, M.Takeo, 他: "The stability characteristics of Bi-based high temperature superconducting coil" Proc.of MT15 (Science Press). Part2. 1056-1059 (1998)

[Publications] T.Nakamura, T.Kiss, Y.Hanayama, 他: "Transport properties in YBa_2Cu_3O_<7-y> superconducting thin films over wode range of electric field" Advances in Superconductivity (Springer-Verlag). 10. 581-584 (1998)

[Publications] Yu.A.Ilyin, T.Nakamura 他: "Critical current distribution along the Bi-2212 high temperature superconducting coil" Advances in Superconductivity (Springer-Verlag). 10. 799-802 (1998)

[Publications] T.Sueyoshi, N.Ishikawa, A.Iwase 他: "Transport characteristics near the glass-liquid transition temperature before and after heavy-iron irradiation in a YBa_2Cu_3O_<7-y> thin film" Physica. C309. 79-88 (1998)

[Publications] T.Kiss, T.Nakamura, K.Hasegawa 他: "Nonlinear resistance in high Tc superconductors as a function of bias current density, temperature and magnetic field" ICEC (IOP Publishing). 17. 427-430 (1998)

[Publications] V.S.Vysotsky, T.Kiss, Yu.A.Ilyin 他: "Heat and quechpropergation in HTSC coils with bobbins from different materials (Part1, Experiment)" ICEC (IOP Publishing). 17. 583-586 (1998)

[Publications] M.Tanouchi, S.Shikii, M.Yamashita 他: "Visualization of optically controlled magnetic flux in YBa_2Cu_3O_<7-d> thin film loop by terahertz radiation imaging" Jpn.J.Appl.Phys.37.Pt.2(11A). 1301-1303 (1998)

[Publications] S.Shikii, T.Kondo, M.Yamashita 他: "Observation of supercurrent distribution in YBa_2Cu_3O_<7-d> thin films using THz radiation excited with femtosecond laser pulses" Appl.Phys.Lett.74(3)(To be published). (1999)

[Publications] O.Morikawa, M.Tonouchi, M.Tani 他: "Sub-THz emission properties of photoconductive antennas excited with multimode laser diode" J.Appl.Phys.Part 1.38(3)(To be published). (1999)

[Publications] K.Develos, M.Kusunoki 他: "Studies on Surface Morphology and Orientation of CeO_2 Films Deposited by Pulsed Laser Ablation" Jpn.J.Appl.Phys.37. 6161-6169 (1998)

[Publications] M.Sugahara, S.Mitani, H.F.Lu 他: "Theory and experimental evidence for pair FQHE state caused by zero-point harmonic oscillation in block-layer potential" Summetry and Pairing in Superconductors (Kluwer). 287-300 (1999)

栗城真也北海道大学, 電子科学研究所, 教授 (30002108)