Construction of mapping systems of superconducting properties under magnetic fields

磁场下超导特性测绘系统的构建

• 批准号: 11554014
• 负责人: HANGYO Masanori
• 金额: $ 8.9万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11554014/
• 关键词: terahertz wave; high-Tc superconductor; supercurrent mapping; magnetic flux; femtosecond laser; photoexcited carrier; semiconductor evaluation; real time imaging; 超短光パルス; 超高速光応答; 高温超伝導体; ポンプ-プローブ分光; 磁束ダイナミクス; テラヘルツイメージ; テラヘルツ時間領域分光法; サブテラヘル

The purpose of this study is to develop systems for visualizing supercurrent based on a femtosecond-laser excited terahertz radiation phenomenon, which we found in 1995. By focusing a laser spot to 20 micrometer in diameter and scanning the spot on a sample with detecting the THz radiation amplitude, we succeeded in visualizing two-dimensional supercurrent flow in high Tg superconducting films. Further, we succeeded in visualizing vector supercurrent flow under the flux trapped state by mapping two mutually orthogonal polarization components of THz radiation. The behavior of the supercurrent measured by this system is explained by the Bean model semi-quantitatively. The imaging system using the focused THz radiation is also developed and applied to visualize the photoexcited carrier distribution in semiconductors. These new applications of THz radiation will contribute to the growing THz technology.

本研究的目的是开发基于飞秒激光激发的太赫兹辐射现象的超电流可视化系统，该现象是我们在1995年发现的。通过将激光光斑聚焦到直径为20 μ m，并在样品上扫描光斑，检测THz辐射幅度，我们成功地可视化了高Tg超导薄膜中的二维超电流流动。此外，我们成功地可视化矢量超电流下的通量捕获状态下映射两个相互正交的偏振分量的太赫兹辐射。用Bean模型半定量地解释了该系统测量的超电流行为。还开发了使用聚焦太赫兹辐射的成像系统，并应用于半导体中光激发载流子分布的可视化。THz辐射的这些新应用将有助于THz技术的发展。

项目成果

T.Kondo: "A novel two-dimensional mapping system for supercurrent distribution using femtosecond laser pulses"Advances in Superconductivity. XI. 1285-1289 (1999)

T.Kondo：“一种使用飞秒激光脉冲进行超电流分布的新型二维绘图系统”超导进展。

O.Morikawa: "Vector imaging of supercurrent flow in YBa_2Cu_3O_<7-δ> thin films using terahertz radiation"Appl. Phys. Lett.. 75. 3387-3389 (1999)

O.Morikawa：“使用太赫兹辐射对 YBa_2Cu_3O_<7-δ> 薄膜中的超电流进行矢量成像”Appl. 75. 3387-3389 (1999)

S.Nashima 他: "Two components in femtosecond optical response of Y_<0.7>Pr_<0.3>Ba_2Cu_3O_<7-δ> thin films in superconducting state"Jpn.J.Appl.Phys.. 39-Pt.2 7A. L663-L666 (2000)

S. Nashima等人：“超导态Y_<0.7>Pr_<0.3>Ba_2Cu_3O_<7-δ>薄膜飞秒光学响应中的两个分量”Jpn.J.Appl.Phys..39-Pt.2 7A .L663-L666（2000）

S.Nashima 他: "Femtosecond optical response of Y_<0.7>Pr_<0.3>Ba_2Cu_3O_<7-δ> thin films"Physica B. 284-288. 931-932 (2000)

S. Nashima等人：“Y_<0.7>Pr_<0.3>Ba_2Cu_3O_<7-δ>薄膜的飞秒光学响应”Physica B.284-288(2000)。

M. Tonouchi et al.: "Detection and storage of femtosecond laser pulse signals by optical magnetic-flux-generation in a YBCO thin film loop"IEEE Trans. on Appl. Supercond.. 9. 4467-4470 (1999)

M. Tonouchi 等人：“通过 YBCO 薄膜环路中的光学磁通量生成来检测和存储飞秒激光脉冲信号”IEEE Trans。