| 研究課題/領域番号 |
15K05140
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| 研究機関 | 国立研究開発法人理化学研究所 |
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研究代表者 |
Kriener Markus 国立研究開発法人理化学研究所, 創発物性科学研究センター, 研究員 (60447919)
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| 研究期間 (年度) |
2015-04-01 – 2019-03-31
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| キーワード | Superconductivity / Polar Semiconductors / Topological Insulators / Topol. Supeconductors / Weyl Semimetals |
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| 研究実績の概要 |
GeTe project: The study on the ferromagnetic phase induced by Mn-doping on the Ge site has been finished and the results were published. The focus was shifted on a collaboration on the closely related topological crystalline insulator SnTe where Indium doping induces superconductivity. So far the superconducting phase diagram was only known up to In concentrations of approx. 45-50% since for higher Indium levels a structural phase transition takes places and superconductivity is lost. By employing a high-pressure synthesis method we successfully grew the whole solid solution up to InTe enabling us to map out the complete phase diagram. An interesting and unexpected two-dome structure of the superconducting phase diagram was revealed. Motivated by theoretical calculations, codoping Se at the Te site was also attempted and Tc was further enhanced. As a possible mechanism the valence-skipping nature of Indium was cinsidered. These results were written up and the paper has been published recently (the first three authors contributed equally to this project). Meanwhile two more collaborations were started focussing on this system (ongoing).
Cd3As2 project: Two collaborations are ongoing. One on the topological aspects of the pure and Zn-doped system lead to four publications with two being published and one accepted for publication. The second collaboration on this system faced some experimental problems and is currently pending.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
The high-pressure synthesis conditions for the targeted doped semiconductor GeTe were successfully established and sample preparation is under control. Also single-crystal preparation on low-In-doped SnTe has worked out well leading to a new collaboration on this system where among others the possible topological nature of this doped system is examined.
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| 今後の研究の推進方策 |
I also started to address In-doping into GeTe. This system was also found to become superconducting. Interestingly the system behaves very different as compared to In-doped SnTe. This project is ongoing, a first publication is in preparation.
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| 次年度使用額が生じた理由 |
The remaining money will be used to attend an international conference where research resulty obtained under this project will be presented. In addition a software program will be purchased to be used under this project.
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