日本原子力研究開発機構システム計算科学センター

システム計算科学センター

永井佑紀 research map

国立研究開発法人日本原子力研究開発機構　システム計算科学センター　シミュレーション技術開発室　副主任研究員

国立研究開発法人理化学研究所　革新知能統合研究センター数理科学チーム　客員研究員

連絡先 Email: Nagai.Yuki_-at.-mark.-_jaea.go.jp ("_"で囲まれた部分を取り去ってください)

略歴 †

2001 私立札幌光星高校卒業

2005 北海道大学工学部応用物理学科卒業（物性物理工学分野：明楽浩史教授）

2007 東京大学大学院理学系研究科物理学専攻修士課程修了（加藤雄介助教授）

2010 東京大学大学院理学系研究科物理学専攻博士課程修了（加藤雄介准教授）

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学位：博士(理学) †

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職歴等 †

2005年度夏学期：物理学B（力学）TA
2006年度冬学期：基礎物理学実験TA
2007年5月16日～6月15日：京都大学基礎物理学研究所アトム型研究員
2007年4月～2008年3月：理化学研究所古崎物性理論研究室JRA（ジュニア・リサーチ・アソシエイト）
2007年度冬学期：基礎物理学実験TA（回数は半分）
2008年4月～日本学術振興会特別研究員(DC2)
2008年度冬学期：基礎物理学実験TA（回数は半分）
2009年度冬学期：基礎物理学実験TA（回数は半分）
2009年度冬学期：英語ALESS Program 実験相談会TA
2016年11月～2017年10月：客員研究員（Visiting Scholar), Department of Physics, Massachusetts Institute of Technology, USA (Host reseacher: Prof. Liang Fu)
2010年4月～：現職
2018年8月～：国立研究開発法人理化学研究所　革新知能統合研究センター数理科学チーム　客員研究員
2019年4月～2020年3月：学習院大学物理学科　非常勤講師　（担当講義:　熱学および統計力学２　物３年（第一学期）　および　熱学および統計力学３　物３年 (第二学期)）

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専門 †

物性理論、特に固体物理

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受賞等 †

2015年3月: 第９回(2015年)日本物理学会若手奨励賞受賞(領域6) LINK
2018年10月: 日本原子力研究開発機構　理事長表彰　研究開発功績賞

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著書 †

"理科のおさらい　物理"、自由国民社 (2008/9) ISBN 978-4426103651
"超伝導磁束状態の物理"、門脇和男編、裳華房 (2017/4) ISBN 978-4-7853-2922-8
"物理学者，機械学習を使うー機械学習・深層学習の物理学への応用ー" (2019/10) ISBN 978-4254131291

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原著論文 †

赤色：永井佑紀

50. Yuki Nagai and Yusuke Kato
Quasiparticle Bound States around Fractional Vortices in s-wave Superconductor
J. Phys. Soc. Jpn. 88, 054707 (2019). link
arXiv:1812.03646

49. Majid Kheirkhah, Yuki Nagai, Chun Chen, Frank Marsiglio
Majorana corner flat bands in two-dimensional second-order topological superconductors
arXiv:1904.00990

48. Yuki Nagai, Masahiko Okumura, and Akinori Tanaka
Self-learning Monte Carlo method with Behler-Parrinello neural networks
arXiv:1807.04955

47. Yuki Nagai and Hiroshi Shinaoka
Smooth self-energy in the exact-diagonalization-based dynamical mean-field theory: Intermediate-representation filtering approach
J. Phys. Soc. Jpn. 88, 064004 (2019). link
arXiv:1806.10316

46. K. Iida, M. Ishikado, Y. Nagai, H. Yoshida, A. D. Christianson, N. Murai, K. Kawashima, Y. Yoshida, H. Eisaki, A. Iyo
Spin Resonance in the New-Structure-Type Iron-Based Superconductor CaKFe4As4
J. Phys. Soc. Jpn. 86, 093703 (2017). link
arXiv:1708.01006

45. Yuki Nagai, Huitao Shen, Yang Qi, Junwei Liu, and Liang Fu
Self-Learning Monte Carlo Method: Continuous-Time Algorithm
Phys. Rev. B 96, 161102(R) (2017). link
Editors' Suggestion and Open Access
arXiv:1705.06724

44. S. L. Goertzen, K. Tanaka, and Y. Nagai
Self-consistent study of Abelian and non-Abelian order in a two-dimensional topological superconductor
Phys. Rev. B 95, 064509 (2017) link
arXiv:1611.01610

43. Y. Nagai, Yukihiro Ota, and K. Tanaka
Time-reversal symmetry breaking and gapped surface states due to spontaneous emergence of new order in d-wave nanoislands
Phys. Rev. B 96, 060503(R) (2016) link
arXiv:1610.05501

42. Howon Kim, Shi-Zeng Lin, Matthias J. Graf, Yoshinori Miyata, Yuki Nagai, Takeo Kato, and Yukio Hasegawa
Electrical Conductivity through a Single Atomic Step Measured with the Proximity-Induced Superconducting Pair Correlation
Phys. Rev. Lett 117, 116802 (2016). link

41. Y. Nagai, Yasushi Shinohara, Yasunori Futamura, and Tetsuya Sakurai
Reduced-Shifted Conjugate-Gradient Method for a Green's Function: Efficient Numerical Approach in a Nano-structured Superconductor
J. Phys. Soc. Jpn. 86, 014708 (2017) link
arXiv:1607.03992

40. Shingo Yonezawa, Kengo Tajiri, Suguru Nakata, Yuki Nagai, Zhiwei Wang, Koji Segawa, Yoichi Ando, and Yoshiteru Maeno
Thermodynamic evidence for nematic superconductivity in CuxBi2Se3
Nature Physics 13, 123 (2017) link
arXiv:1602.08941

39. Evan D. B. Smith, K. Tanaka, and Y. Nagai
Manifestation of chirality in the vortex lattice in a two-dimensional topological superconductor
Phys. Rev. B 94, 064515 (2016). link
arXiv:1605.08934

38. Y. Nagai and Y. Ota
Nuclear magnetic relaxation rates of unconventional superconductivity in doped topological insulators
Phys. Rev. B 94, 134516 (2016). link
arXiv:1605.08164

37. Yuki Nagai, Shintaro Hoshino, and Yukihiro Ota
Critical Temperature Enhancement of Topological Superconductors: A Dynamical Mean Field Study
Phys. Rev. B 93, 220505(R) (2016). link
arXiv:1602.06087

36. Yoichi Higashi, Yuki Nagai, Tomohiro Yoshida, Yusuke Masaki, and Youichi Yanase
Robust zero-energy bound states around a pair-density-wave vortex core in locally noncentrosymmetric superconductors
Phys. Rev. B 93, 104529 (2016). link arXiv:1602.00425

35. A. Shitade and Y. Nagai
Orbital angular momentum in a topological superconductor with Chern number higher than 1
Phys. Rev. B 93, 174517 (2016). link
arXiv:1512.07997

34. Y. Nagai, and H. Nakamura
Multi-band Eilenberger theory of superconductivity: Systematic low-energy projection
J. Phys. Soc. Jpn. 85, 074707 (2016). link
arXiv:1507.06039

33. Y. Nagai, H. Nakamura, M. Machida, and K. Kuroki
First-principle study of antimony doping effects on the iron-based superconductor CaFe(SbxAs1-x)2
J. Phys. Soc. Jpn. 84, 093702 (2015). link
arXiv:1506.08515

32. Y. Nagai, Y. Ota, and M. Machida
Inverse coherence effects in nuclear magnetic relaxation rates as a sign of topological superconductivity
Phys. Rev. B 92, 180502(R) (2015). link
arXiv:1504.08095

31. A. Shitade and Y. Nagai
Orbital angular momentum in a nonchiral topological superconductor
Phys. Rev. B 92, 024502 (2015). link
arXiv:1501.06677

30. Y. Nagai, H. Nakamura, M. Machida
Surface states around a vortex in topological superconductors: Intersection of a surface and a vortex
J. Phys. Soc. Jpn. 84, 033703 (2015). link
arXiv:1412.5713

29. Y. Nagai
Robust superconductivity with nodes in the superconducting topological insulator CuxBi2Se3: Zeeman orbital field and non-magnetic impurities
Phys. Rev. B 91, 060502(R) (2015). link
arXiv:1410.4646

28. Y. Nagai, Y. Ota, and M. Machida
Topological s-wave pairing superconductivity with spatial inhomogeneity: Mid-gap-state appearance and Anderson's theorem
J. Phys. Soc. Jpn. 84, 034711 (2015). link
arXiv:1407.1125

27. S. Yoshizawa, H. Kim, T. Kawakami, Y. Nagai, T. Nakayama, X. Hu, Y. Hasegawa, and T. Uchihashi
Direct Observation of Josephson Vortices on the Surface Superconductor Si(111)-(root7xroot3)-In by Scanning Tunneling Microscopy
Phys. Rev. Lett. 113, 247004. link
Featured in Physics and Editors' Suggestion
"Ultrathin Superconductors Take a Step Up"
arXiv:1405.5953

26. Y. Nagai
Field-angle-dependent low-energy excitations around a vortex in the superconducting topological insulator CuxBi2Se3
J. Phys. Soc. Jpn. 83 (2014) 063705. link
arXiv:1404.6874

25. Y. Nagai, Y. Ota, and M. Machida
From p- to s-wave behaviors in a three-dimensional topological superconductor with non-magnetic impurities
Phys. Rev. B 89, 214506 (2014) 214506. link
arXiv:1404.1662

24. Y. Nagai, Y. Ota, and M. Machida
Impurity effects in a two-dimensional topological superconductor: A link of Tc-robustness with a topological number
J. Phys. Soc. Jpn. 83 (2014) 094722. link
arXiv:1312.3065

23. Y. Nagai, H. Nakamura, M. Machida
Quasiclassical Treatment and Odd-parity/Triplet Correspondence in Topological Superconductors
J. Phys. Soc. Jpn. 83 (2014) 053705. link
arXiv:1305.3025

22. Y. Higashi, Y. Nagai, M. Machida, N. Hayashi
Field-angle Resolved Flux-flow Resistivity as a Phase-sensitive Probe of Unconventional Cooper Pairing
Phys. Rev. B 88 (2013) 224511. link
arXiv:1304.6509

21. Y. Nagai, Yasushi Shinohara, Yasunori Futamura, Yukihiro Ota, and Tetsuya Sakurai
Numerical construction of a low-energy effective Hamiltonian in a self-consistent Bogoliubov-de Gennes approach of superconductivity
J. Phys. Soc. Jpn. 82 (2013) 094701. link
arXiv:1303.3683

20. Y. Nagai, H. Nakamura, and M. Machida
Spin-polarized Majorana Bound States around a Vortex in Topological Superconductors
J. Phys. Soc. Jpn. 83 (2014) 064703. link
Papers of Editors' Choice
"Hunting Majorana Fermions in Topological Superconductors" in JPSJ News and Comments
arXiv:1211.0125

19. Y. Nagai, H. Nakamura, and M. Machida
Rotational Isotropy Breaking as Proof for Spin-polarized Cooper Pair in Topological Superconductor CuxBi2Se3
Phys. Rev. B 86 (2012) 094507. link
arXiv:1206.0563

18. Y. Nagai, K. Tanaka, and N. Hayashi
Quasiclassical numerical method for mesoscopic superconductors: bound states in a circular d-wave island with a single vortex
Phys. Rev. B 86 (2012) 094526. link
arXiv:1202.2661

17. Y. Nagai, and K. Kuroki
Q-scan-analysis of the neutron scattering in iron-based superconductors
Phys. Rev. B 85 (2012) 134521. link
arXiv:1201.2453

16 Y. Nagai, Y. Ota, and M. Machida
Efficient Numerical Self-consistent Mean-field Approach for Fermionic Many-body Systems by Polynomial Expansion on Spectral Density
J. Phys. Soc. Jpn. 81 (2012) 024710. link
arXiv:1105.4939

15 Y. Nagai, N. Nakai, and M. Machida
Direct Numerical Demonstration of Sign-preserving Quasiparticle Interference via Impurity inside Vortex Core in Unconventional Superconductors
Phys. Rev. B 85 (2012) 092505. link
arXiv:1103.5842

14. Y. Nagai, and K. Kuroki
Determination of the pairing state in iron-based superconductors through neutron scattering
Phys. Rev. B 83 (2011) 220516(R). link
arXiv:1103.0586

13. Y. Nagai, H. Nakamura, and M. Machida
Superconducting Gap Function in an Organic Superconductor (TMTSF)2ClO4 with Anion Ordering; First-principles Calculations and Quasi-classical Analyses for Angle-resolved Heat Capacity
Phys. Rev. B 83 (2011) 104523. link
arXiv:1101.2277

12. M. Ishikado, Y. Nagai, K. Kodama, R. Kajimoto, M. Nakamura, Y. Inamura, S. Wakimoto, H. Nakamura, M. Machida, K. Suzuki, H. Usui, K. Kuroki, A. Iyo, H. Eisaki, M. Arai, S. Shamoto
s±-like spin resonance in the iron-based nodal superconductor BaFe2(As0.65P0.35)2 observed using inelastic neutron scattering
Phys. Rev. B 84 (2011) 144517. link
arXiv:1011.3191

11. Y. Imai, H. Takahashi, K. Kitagawa, K. Matsubayashi, N. Nakai, Y. Nagai, Y. Uwatoko, M. Machida, A. Maeda
Microwave Surface Impedance Measurements of LiFeAs Single Crystals
J. Phys. Soc. Jpn. 80 (2011) 013704. link
arXiv:1009.4628

10. M. Kunimi, Y. Nagai , and Y. Kato
Josephson effects in one-dimensional supersolids
Phys. Rev. B 84 (2011) 094521. link
arXiv:1005.3936

9. N. Nakai, H. Nakamura, Y. Ota, Y. Nagai , N. Hayashi and M. Machida
First-principles-based pm s-wave modeling for iron-based superconductors:Studies for specific heat and nuclear magnetic relaxation rate
Phys. Rev. B 82 (2010) 094501. [link]
arXiv:0909.1195

8. Y. Nagai and Y. Kato
Impurity scattering rate and coherence factor in vortex core of sign-reversing s-wave superconductors
Phys. Rev. B 82 (2010) 174507. [link]
arXiv:0908.4451

7. S. Nakakura, Y. Nagai and D. Yoshioka
Uniform current in graphene strip with zigzag edges
J. Phys. Soc. Jpn. 78 (2009) 065003. [link]
arXiv:0903.1483

6. Y. Nagai and N. Hayashi
Surface Bound States in n-band Systems with Quasiclassical Approach
Phys. Rev. B 79 (2009) 224508. [link]
arXiv:0903.1227

5. Y. Nagai, N. Hayashi, N. Nakai, H. Nakamura, M. Okumura and M. Machida
Nuclear magnetic relaxation and superfluid density in Fe-pnictide superconductors: An anisotropic \pm s-wave scenario New J. Phys. 10 (2008) 103026. [link] arXiv:0809.1197

4. Y. Nagai and N. Hayashi Kramer-Pesch approximation for analyzing field-angle-resolved measurements made in unconventional superconductors: A calculation of the zero-energy density of states
Phys. Rev. Lett. 101 (2008) 097001. [link]
arXiv:0802.1579

3. Y. Nagai, Y. Kato, N. Hayashi, K. Yamauchi and H. Harima
Calculated Positions of Point Nodes in the Gap Structure of the Borocarbide Superconductor YNi2B2C
Phys. Rev. B 76, (2007) 214514. [link]
arXiv:0706.1863

2. Y. Nagai, Y. Ueno, Y. Kato and N. Hayashi
Analytical Formulation of the Local Density of States around a Vortex Core in Unconventional Superconductors
J. Phys. Soc. Jpn. 75 (2006) 104701.[link]
cond-mat/0605441

1. Y. Nagai, Y. Kato and N. Hayashi
Analytical Result on Electronic States around a Vortex Core in a Noncentrosymmetric Superconductor
J. Phys. Soc. Jpn. 75 (2006) 043706 [link]
cond-mat/0602254

永井 佑紀