Theoretical investigation for exotic phases in superconductors and superfluids with multiple components and multiple bands

• Project/Area Number: 26400360
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Condensed matter physics II
• Research Institution: Ritsumeikan University (2015-2017); Okayama University (2014)
• Principal Investigator: Machida Kazushige 立命館大学, 理工学部, 非常勤講師 (50025491)
• Project Period (FY): 2014-04-01 – 2018-03-31
• Project Status: Completed (Fiscal Year 2017)
• Budget Amount: ¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000); Fiscal Year 2017: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2016: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2015: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2014: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
• Keywords: 重い電子系 / 超伝導 / 対関数 / ギャップ構造 / 対称性 / 渦格子 / 超伝導体

Outline of Final Research Achievements

Several exotic superconductors, including CeCu2Si2, UPd2Al3, (U,Th)Be13 for typical heavy Fermion superconducting materials and highly two-dimensional Sr2RuO4 known for chiral triplet superconductor candidate are investigated theoretically in collaboration with experimental groups. In addition to it, we also studies FeSe among iron pnictide superconductors and SrBi2Se3 for topological material candidates. We have succeeded in identifying possible pairing symmetries realized in some of those materials, which are fully consistent with the experimental data of angle-resolved specific heat measurements done by collaborating experimental groups.

Research Products

• [Journal Article] Symmetry-Protected Topological Superfluids and Superconductors -From the Basics to 3He- (2016)
  • Author(s): T. Mizushima, Y. Tsutsumi, T. Kawakami, M. Sato, M. Ichioka, and K. Machida
  • Journal Title: Journal of the Physical Society of Japan Volume: 85 Issue: 2 Pages: 022001-022001
  • DOI: 10.7566/jpsj.85.022001
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Eilenberger theory for nuclear magnetic relaxation rate in superconducting vortex lattice state (2015)
  • Author(s): Kenta Tanaka, Masanori Ichioka, Seiichiro Onari, Noriyuki Nakai, and Kazushige Machida
  • Journal Title: Physical Review B Volume: 91 Issue: 1
  • DOI: 10.1103/physrevb.91.014509
  • Peer Reviewed
• [Journal Article] Pauli paramagnetic effects on mixed-state properties in a strongly anisotropic superconductor: Application to Sr2RuO4 (2015)
  • Author(s): Y. Amano, M. Ishihara, M. Ichioka, N. Nakai, and K. Machida
  • Journal Title: Phys. Rev. B Volume: 91 Issue: 14
  • DOI: 10.1103/physrevb.91.144513
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Hidden crossover phenomena in strongly Pauli-limited multiband superconductors: Application to CeCu2Si2 (2015)
  • Author(s): Y. Tsutsumi, K. Machida, and M. Ichioka
  • Journal Title: Phys. Rev. B Volume: 92 Issue: 2
  • DOI: 10.1103/physrevb.92.020502
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Interplay between effective mass anisotropy and Pauli paramagnetic effects in a multiband superconductor: Application to Sr2RuO4 (2015)
  • Author(s): N. Nakai, and K. Machida
  • Journal Title: Phys. Rev. B Volume: 92 Issue: 5
  • DOI: 10.1103/physrevb.92.054505
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Field-Orientation Dependence of Low-Energy Quasiparticle Excitations in the Heavy-Electron Superconductor UBe13 (2015)
  • Author(s): Y. Shimizu, S. Kittaka, T. Sakakibara, Y. Haga, E. Yamamoto, H. Amitsuka, Y. Tsutsumi, and K. Machida
  • Journal Title: Phys. Rev. Lett. Volume: 114 Issue: 14
  • DOI: 10.1103/physrevlett.114.147002
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Multiband superconductivity with unexpected deficiency of nodal quasiparticles in CeCu2Si2 (2014)
  • Author(s): S. Kittaka, Y. Aoki, Y. Shimura, T. Sakakibara, S. Seiro, C. Geibel, F. Steglich, H. Ikeda, and K. Machida
  • Journal Title: Phys. Rev. Lett. Volume: 112 Issue: 6 Pages: 067002-067002
  • DOI: 10.1103/physrevlett.112.067002
  • Peer Reviewed