Application of electron pair breaking by photon for terahertz wave detection

2017 Fiscal Year Final Research Report

• Project/Area Number: 16K13659
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Applied materials
• Research Institution: Yamagata University
• Principal Investigator: NAKAJIMA Kensuke 山形大学, 大学院理工学研究科, 教授 (70198084)
• Co-Investigator(Kenkyū-buntansha): 山田 博信 山形大学, 大学院理工学研究科, 助教 (50400411)
• Project Period (FY): 2016-04-01 – 2018-03-31
• Keywords: テラヘルツ波 / 超伝導 / 検出器

Outline of Final Research Achievements

Bismuth Cuprate High-Tc superconductors (Bi-HTS) reveal a peculiar RF response just below the superconducting transition temperature. In this research, we studied response mechanism and developing high quality nm-thick Bi-HTS thin films required for bolometer aiming at applying this to terahertz sensitive bolometers operating at 77K. We choose Neodymium Gallate (NGO: NdGaO3) as favorable substrates for epitaxial growth by Metal Organic Decomposition (MOD) method with low dielectric loss and good transparency in the terahertz wave range. At the first we encountered a serious problem that Ga ion diffused in Bi-HTS and totally inhibited its superconductivity. By using the non-superconducting Bi-HTS film as a self-buffer layer to overcome the problem, we succeeded to have epitaxially grown quality 10nm-thick Bi-HTS thin films exhibiting superconducting transition at 75K.

Free Research Field

超伝導エレクトロニクス