| 研究内容 |
NMRによる超伝導体の研究 |
| 研究で一番うれしかったことと一番辛かったこと |
嬉しかった事：信号が見えたとき 辛かった事：信号がいないとき |
| ひとこと |
研究頑張ります。 |
このグループの私の出版物
2022
2.
A Ikeda, S Ranjan Saha, D Graf, P Saraf, D Sergeevich Sokratov, Y Hu, H Takahashi, S Yamane, A Jayaraj, J Sławińska, M Buongiorno Nardelli, S Yonezawa, Y Maeno, J Paglione
Quasi-two-dimensional Fermi surface of superconducting line-nodal metal CaSb2 Journal Article
In: Physical Review B, vol. 106, iss. 7, pp. 075151, 2022.
@article{A.Ikeda_PRB_2022,
title = {Quasi-two-dimensional Fermi surface of superconducting line-nodal metal CaSb2},
author = {A Ikeda and S Ranjan Saha and D Graf and P Saraf and D Sergeevich Sokratov and Y Hu and H Takahashi and S Yamane and A Jayaraj and J Sławińska and M Buongiorno Nardelli and S Yonezawa and Y Maeno and J Paglione},
url = {https://arxiv.org/abs/2206.15346},
doi = {10.1103/PhysRevB.106.075151},
year = {2022},
date = {2022-08-29},
urldate = {2022-08-29},
journal = {Physical Review B},
volume = {106},
issue = {7},
pages = {075151},
abstract = {We report on the Fermi surfaces and superconducting parameters of CaSb2 single crystals (superconducting below Tc ∼ 1.8 K) grown by the self-flux method. The frequency of de Haas–van Alphen and Shubnikov–de Haas oscillations evidences a quasi-two-dimensional (quasi-2D) Fermi surface, consistent with one of the Fermi surfaces forming Dirac lines predicted by first-principles calculations. Measurements in the superconducting state reveal that CaSb2 is close to a type-I superconductor with the Ginzburg-Landau parameter of around unity. The temperature dependence of the upper critical field Hc2 is well described by a model considering two superconducting bands, and the enhancement of the effective mass estimated from Hc2 (0 K) is consistent with the quasi-2D band observed by the quantum oscillations. Our results indicate that a quasi-2D band forming Dirac lines contributes to the superconductivity in CaSb2.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We report on the Fermi surfaces and superconducting parameters of CaSb2 single crystals (superconducting below Tc ∼ 1.8 K) grown by the self-flux method. The frequency of de Haas–van Alphen and Shubnikov–de Haas oscillations evidences a quasi-two-dimensional (quasi-2D) Fermi surface, consistent with one of the Fermi surfaces forming Dirac lines predicted by first-principles calculations. Measurements in the superconducting state reveal that CaSb2 is close to a type-I superconductor with the Ginzburg-Landau parameter of around unity. The temperature dependence of the upper critical field Hc2 is well described by a model considering two superconducting bands, and the enhancement of the effective mass estimated from Hc2 (0 K) is consistent with the quasi-2D band observed by the quantum oscillations. Our results indicate that a quasi-2D band forming Dirac lines contributes to the superconductivity in CaSb2.
2021
1.
H Takahashi, S Kitagawa, K Ishida, M Kawaguchi, A Ikeda, S Yonezawa, Y Maeno
S-Wave Superconductivity in the Dirac Line-Nodal Material CaSb2 Journal Article
In: Journal of the Physical Society of Japan, vol. 90, pp. 073702, 2021.
@article{H.Takahashi_JPSJ_2021,
title = {S-Wave Superconductivity in the Dirac Line-Nodal Material CaSb2},
author = {H Takahashi and S Kitagawa and K Ishida and M Kawaguchi and A Ikeda and S Yonezawa and Y Maeno},
url = {https://arxiv.org/abs/2105.13614},
doi = {10.7566/JPSJ.90.073702},
year = {2021},
date = {2021-06-11},
urldate = {2021-06-11},
journal = {Journal of the Physical Society of Japan},
volume = {90},
pages = {073702},
abstract = {We performed 121/123Sb-nuclear quadrupole resonance (NQR) measurements on the superconducting (SC) line-nodal material CaSb2 in order to investigate electronic properties in the normal and SC states from a microscopic point of view. In the normal state, the nuclear spin–lattice relaxation rate 1/T1 for the Sb(1) site, which is responsible for the line-nodal parts, is approximately proportional to temperature, indicating the conventional Fermi liquid state. From comparison with band structure calculations, it is considered that the NQR properties related to the line-nodal character are hidden because the conventional behavior originating from Fermi-surface parts away from the nodes is dominant. In the SC state, a clear coherence peak just below the transition temperature and an exponential decrease at lower temperatures were observed in 1/T1. These results strongly suggest that conventional s-wave superconductivity with a full gap is realized in CaSb2.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We performed 121/123Sb-nuclear quadrupole resonance (NQR) measurements on the superconducting (SC) line-nodal material CaSb2 in order to investigate electronic properties in the normal and SC states from a microscopic point of view. In the normal state, the nuclear spin–lattice relaxation rate 1/T1 for the Sb(1) site, which is responsible for the line-nodal parts, is approximately proportional to temperature, indicating the conventional Fermi liquid state. From comparison with band structure calculations, it is considered that the NQR properties related to the line-nodal character are hidden because the conventional behavior originating from Fermi-surface parts away from the nodes is dominant. In the SC state, a clear coherence peak just below the transition temperature and an exponential decrease at lower temperatures were observed in 1/T1. These results strongly suggest that conventional s-wave superconductivity with a full gap is realized in CaSb2.
