A transparent superconductor: mechanism and possible applications
| Project/Area Number |
26610092
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| Research Category |
Grant-in-Aid for Challenging Exploratory Research
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| Allocation Type | Multi-year Fund |
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| Research Field |
Condensed matter physics II
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| Research Institution | Tohoku University |
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Principal Investigator |
Hitosugi Taro 東北大学, 原子分子材料科学高等研究機構, 准教授 (90372416)
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| Project Period (FY) |
2014-04-01 – 2016-03-31
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| Project Status |
Completed (Fiscal Year 2015)
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| Budget Amount *help |
¥3,380,000 (Direct Cost: ¥2,600,000、Indirect Cost: ¥780,000)
Fiscal Year 2015: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2014: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
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| Keywords | 透明導電体 / 透明超伝導 / 薄膜 / 酸化物 / 超伝導 / 透明超伝導体 / 走査トンネル顕微鏡 / 光学特性 / 光学 |
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| Outline of Final Research Achievements |
A framework is presented for the transparent conducting mechanism of transparent superconductor LiTi2O4. In the Bardeen-Cooper-Schrieffer (BCS) framework, achieving high superconducting transition temperature requires a large carrier density at the Fermi energy. This requirement prohibits the emergence of transparent superconductivity at high temperature, since the large carrier density leads to the optical absorption in the visible region. However, we here demonstrate transparent superconducting properties with a transition temperature exceeding 13 K in spinel LiTi2O4(111) epitaxial thin films. Although the LiTi2O4 have a very large carrier density exceeding 10 22 cm-3, the film shows high transmittance in the visible region. Photoemission and optical studies indicate a band gap of ~3.3 eV with free electrons populating up to 0.5 eV from the bottom of the conduction band. Electron transport measurements and optical analyses suggest the key role of electron effective mass.
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Report
(3 results)
Research Products
(3 results)
