Theoretical Study of Phase Transition in Superconducting Vortex States

超导涡旋态相变的理论研究

• 批准号: 12640347
• 负责人: IKEDA Ryusuke
• 金额: $ 1.15万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12640347/
• 关键词: Cuprate Superconductor; Organic Superconductor; Quantum fluctuation; Transport properties; 超伝導; 渦糸; 量子揺らぎ; 渦糸状態; 渦糸グラス転移; ジョセフソン渦糸; スピン三重項超伝導; 量子相転移

In the first year, 2000, I have studied two subjects on the vortex states in three-dimensional layered superconductors. First, I have given n theory on a transition to a glass phase of Josephson vortices induced by an applied field parallel to the layers. Recently, this theory has been justified by a couple of domestic sad foreign experimental works. Next, a theory explaining a material dependence of vortex phase diagram in fields perpendicular to the layers was proposed, and, consistently with experimental results on superconducting YBaCuOs, the presence of a lower critical point of the first order transition line was argued.In 2001 and 2002, our main interests have moved onto quantum superconducting fluctuation effects in vortex states. First, one of my students (H.Ishida) and I have formulated a microscopic theory applicable to the superconductor-insulator transition behavior induced by a magnetic field in amorphous superconducting films with s-wave pairing and have qualitatively explained the corresponding resistive phenomena. Further, this theory was phenomenologically extended to superconducting cuprates and organics of which the microscopic mechanisms are still controversial, and anomalous transport phenomena in the vortex liquid regime of these materials with very low condensation energy were shown to arise from the strong quantum fluctuation effect at finite temperatures.

第一年，2000年，我研究了三维层状超导体中涡旋态的两个课题。首先，我给出了由平行于层的外加场引起的约瑟夫森涡旋向玻璃相转变的理论。最近，这一理论被国内几件令人悲哀的国外实验作品所证实。接下来，提出了一种解释垂直于层的场中涡旋相图的材料依赖性的理论，并且与超导 YBaCuO 的实验结果一致，论证了一级转变线的下临界点的存在。 2001 年和2002年，我们的主要兴趣转移到涡旋态的量子超导涨落效应上。首先，我和我的一位学生（H.Ishida）提出了一种适用于具有 s 波配对的非晶超导薄膜中由磁场引起的超导体-绝缘体转变行为的微观理论，并定性地解释了相应的电阻现象。此外，该理论在现象学上扩展到超导铜酸盐和有机物，其微观机制仍存在争议，并且这些具有非常低凝聚能的材料的涡旋液体状态中的反常输运现象被证明是由有限温度下的强量子涨落效应引起的。温度。

项目成果

H.Ishida, H.Adachi, R.Ikeda: "Microscopic Study of Quantum Vortex-Glass Transition Field in Two-Dimensional Superconductors"Journal of the Physical Society of Japan 誌. 71・1. 245-253 (2002)

H.Ishida、H.Adachi、R​​.Ikeda：“二维超导体中量子涡旋-玻璃转变场的微观研究”日本物理学会杂志71・1（2002）。

H.Ishida, R.Ideda: "Theoretical Description of Resistive Behavior near a Quantum Vortex-Glass Transition"Journal of the Physical Society of Japan 誌. 71・1. 254-264 (2002)

H.Ishida、R.Ideda：“量子涡旋-玻璃转变附近的电阻行为的理论描述”日本物理学会杂志 71・1（2002 年）。

H.Adachi, R.Ikeda: "Fluctuation Conductivity in Unconventional Superconductors near Critical Disorder"Journal of the Physical Society of Japan 誌. 70・10. 2848-2851 (2001)

H.Adachi、R​​.Ikeda：“临界紊乱附近的非常规超导体的波动电导率”日本物理学会杂志 70・10 2848-2851（2001）。

Ryusuke Ikeda: "Fluctuation Effects in Underdoped Cuprate Superconductors under a Magnetic Field"Physical Review B 誌. 66・10. 100511 (2002)

池田龙介：“磁场下欠掺杂铜酸盐超导体的涨落效应”《物理评论 B》杂志 66・10（2002 年）。

Ryusuke Ikeda: "Comment on Disorder and Quantum Fluctuations in Superconducting Films in Strong Magnetic Fields"Physical Review Letters. Vol.86,No.10. 10 (2002)

池田龙介：《强磁场中超导薄膜的无序和量子涨落评述》物理评论快报。