| 研究課題/領域番号 |
21K04873
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| 研究機関 | 東北大学 |
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研究代表者 |
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| 研究分担者 |
米田 忠弘 東北大学, 多元物質科学研究所, 教授 (30312234)
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| 研究期間 (年度) |
2021-04-01 – 2024-03-31
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| キーワード | SC-PAT / superconductor / YSR |
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| 研究実績の概要 |
To understand the spin properties with atomic scale resolution, the characterization of the superconductor substrate is important. We found a 1T phase island of NbSe2 on a cleaved surface and its magnetic properties. Tunneling spectroscopy at 400 mK shows robust peaks in the superconducting gap, which we assign to the Yu-Shiba-Rusinov (YSR) state originating from the magnetic moment in the superconducting state. The YSR peak appears on a specific position of an island of the 1T phase, not on the surrounding 2H phase area. We assign the origin of the magnetic moment to the curvature of the 1T phase island, which can form a magnetic moment through a rotation of the wave function by a robust spin-orbit coupling, as indicated by a recent theoretical study.
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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
SC-PAT microscopy is expected to detect the difference in spin chemical environment with atomic resolution. To develop that, a clear understanding of the superconducting substrate and spin properties using usual STM and STS was our primary goal. We could achieve the goal smoothly and forwarded for final goal. Co-investigator Prof Tadahiro Komeda is highly experienced for the STM and STS techniques for spin detection and have nice experimental facilities. Although there were trouble due to covid situation but the goal could be achieved smoothly due to smooth operations in experimental facilities.
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| 今後の研究の推進方策 |
We successfully determined the exchange interaction energy (Eex) between the spins of the radical ligand (Pc) and the center 4f metal atom (Tb3+) by using the IETS technique. Then, we found a 1T phase island of NbSe2 substrate on a cleaved surface and its magnetic properties. Tunneling spectroscopy at 400 mK shows robust Yu-Shiba-Rusinov (YSR) peaks in the superconducting gap, which confirmed the magnetic moment in the superconducting state due to the local curvature of the island. We started the study of TbPc2 molecule on another superconductor substrate, Pb, to realize different chemical environment of spin. In near future experiments, we will use the RF in the tunnel junction to measure the dI/dV with the variation of RF power for the different position within molecule and also depending on the substrate. Using SC-PAT, we expect to detect the chemical variation of spin in different position within molecule and when molecule on different substrates. We can utilize our current result to build the SC-PAT system using STM.
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