Development of high-resolution photoemission spectroscopy for small-size superconductor

2010 Fiscal Year Final Research Report

• Project/Area Number: 20684014
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Condensed matter physics II
• Research Institution: Tohoku University
• Principal Investigator: SOUMA Seigo 東北大学, 原子分子材料科学高等研究機構, 助教 (20431489)
• Project Period (FY): 2008 – 2010
• Keywords: 角度分解光電子分光 / 超伝導 / 強相関電子系

Research Abstract

To investigate the electronic structure of superconductors which has experimental difficulty such as tiny size of crystal and/or absence cleavage plane, we have developed experimental techniques and apparatus for high-resolution angle resolved photoemission spectroscopy on a small-size sample. As a result, we have succeeded in directly observing the basal electronic structure and/or superconducting gap for recently discovered exotic compounds such as Fe-pnictide superconductors and cement C12A7 electride.

Research Products

• [Journal Article] Fermi surface dichotomy of the superconducting gap and pseudogap in underdoped pnictides (2011)
  • Author(s): Y. -M. Xu, P. Richard, K. Nakayama, T. Kawahara, Y. Sekiba, T. Qian, M. Neupane, S. Souma, T. Sato, T. Takahashi, H. -Q. Luo, H. -H. Wen, G. -F. Chen, N. -L. Wang, Z. Wang, Z. Fang, X. Dai, H. Ding
  • Journal Title: Nat. Commun. Volume: 2 Pages: 392
  • Peer Reviewed
• [Journal Article] Direct evidence for cage conduction band in superconducting cement 12Cao・7Al_2O_3 by low-energy high-resolution photoemission spectroscopy (2010)
  • Author(s): S. Souma, T. Arakane, T. Sato, T. Takahashi, S. W. Kim, S. Matsuishi, H. Hosono
  • Journal Title: J. Phys. Soc. Jpan. Volume: 79 Pages: 103704
  • Peer Reviewed
• [Journal Article] Van Hove Singularities as a Result of Quantum Confinement: The Origin of Intriguing Physical Properties in Pb Thin Films (2010)
  • Author(s): Yu Jie Sun, S. Souma, Wen Juan Li, T. Sato, Xie Gang Zhu, Guang Wang, Xi Chen, Xu Cun Ma, Qi Kun Xue and Jin Feng Jia, T. Takahashi, T. Sakurai
  • Journal Title: Nano Res. Volume: 3 Pages: 800
  • Peer Reviewed
• [Journal Article] Ultrahigh-resolution spin-resolved photo-emission spectrometer with a mini Mott detector (2010)
  • Author(s): S. Souma, A. Takayama, K. Sugawara, T. Sato, T. Takahashi
  • Journal Title: Rev. Sci. Instrum. Volume: 81 Pages: 095101
  • Peer Reviewed
• [Journal Article] Direct evidence for the Dirac-cone topological surface states in the ternary chalcogenide TlBiSe_2 (2010)
  • Author(s): T. Sato, K. Segawa, H. Guo, K. Sugawara,S. Souma, T. Takahashi, Y. Ando
  • Journal Title: Phys. Rev. Lett. Volume: 105 Pages: 136802
  • Peer Reviewed
• [Journal Article] Pseudogap of charge-density-wave compound SmNiC_2 studied by high-resolution photo-emission spectroscopy (2010)
  • Author(s): T. Sato, S. Souma, K. Nakayama, T. Takahashi, S. Shimomura, H. Onodera
  • Journal Title: J. Phys. Soc. Jpn. Volume: 79 Pages: 044707
  • Peer Reviewed
• [Journal Article] Superconducting-gap symmetry of Ba_<0.6>K_<0.4>Fe_2As_2 studied by angle-resolved photoemission spectroscopy (2009)
  • Author(s): K. Nakayama, T. Sato, P. Richard, Y.-M. Xu, Y. Sekiba, S. Souma, G. F. Chen, J. L. Luo, N. L. Wang, H. Ding, T. Takahashi
  • Journal Title: Europhys. Lett. Volume: 85 Pages: 67002
  • Peer Reviewed
• [Journal Article] Angle-Resolved Photoemission Spectroscopy of the Fe-Based Ba_<0.6>K_<0.4>Fe_2As_2High Temperature Superconductor: Evidence for an Orbital Selective Electron-Mode Coupling (2009)
  • Author(s): P. Richard, T. Sato, K. Nakayama, S. Souma, T. Takahashi, Y. -M. Xu, G. F. Chen, J. L. Luo, N. L. Wang, H. Ding
  • Journal Title: Phys. Rev. Lett. Volume: 102 Pages: 047003
  • Peer Reviewed
• [Journal Article] Magnetic Phase Transition of CeSb Studied by Low-Energy Angle-Resolved Photo-emission Spectroscopy (2009)
  • Author(s): A. Takayama, S. Souma, T. Sato, T. Arakane, and T. Takahashi
  • Journal Title: J. Phys. Soc. Jpn. Volume: 78 Pages: 073702
  • Peer Reviewed
• [Journal Article] Metal-insulator transition of Na_xWO_3 studied by angle-resolved photoemission spectroscopy (2009)
  • Author(s): S. Raji, T. Sato, S. Souma, T. Takahashi, D. D. Sarma, P. Mahadevan
  • Journal Title: Mod. Phys. Lett. Volume: B23 Pages: 2819
  • Peer Reviewed
• [Journal Article] Band structure and Fermi surface of an extremely overdoped iron-based super-conductor KFe_2As_2 (2009)
  • Author(s): T. Sato, K. Nakayama, Y. Sekiba, P. Richard, Y.-M. Xu, S. Souma, T. Takahashi, G. F. Chen, J. L. Luo, N. L. Wang, H. Ding
  • Journal Title: Phys. Rev. Lett. Volume: 103 Pages: 047002
  • Peer Reviewed
• [Journal Article] Band structure and Fermi surface of heavy Fermion compounds Ce_2TIn_8 (T=Co, Rh, In) studied by angle-resolved photoemission spectroscopy (2008)
  • Author(s): S. Souma,S. Ra j, J. C. Campuzano, T. Sato, T. Takahashi, S. Ohara, S. Sakamoto
  • Journal Title: Physica B Volume: 403 Pages: 752
  • Peer Reviewed
• [Journal Article] Low-energy excitations in graphite studied by ultrahigh-resolution angle-resolved photoemission spectroscopy (2008)
  • Author(s): K. Sugawara, T. Sato, S. Souma, T. Takahashi, H. Suematsu
  • Journal Title: Physica B Volume: 403 Pages: 1531
  • Peer Reviewed
• [Journal Article] Quasiparticle lifetime in graphite studied by ultrahigh-resolution ARPES (2008)
  • Author(s): K. Sugawara, T. Sato, S. Souma, T. Takahashi, H. Suematsu
  • Journal Title: J. Phys. Chem. Solids Volume: 69 Pages: 2996
  • Peer Reviewed
• [Journal Article] Cooperative structural and Peierls transition of Indium chains on Si(111) surface (2008)
  • Author(s): Y. J. Sun, S. Agario, S. Souma, K. Sugawara, Y. Tago, T. Sato, T. Takahashi
  • Journal Title: Phys. Rev. B Volume: 77 Pages: 125115
  • Peer Reviewed
• [Journal Article] Superconducting Gap and Pseudogap in Iron-Based Layered Superconductor La(O_<1-x>F_x)FeAs (2008)
  • Author(s): T. Sato, S. Souma, K. Nakayama, K. Terashima, K. Sugawara, T. Takahashi, Y. Kamihara, M. Hirano, H. Hosono
  • Journal Title: J. Phys. Soc. Jpn. Volume: 77 Pages: 063708
  • Peer Reviewed
• [Journal Article] Observation of Fermi-surface-dependent nodeless superconducting gaps in Ba_<0.6>K_<0.4>Fe_2As_2 (2008)
  • Author(s): H. Ding, P. Richard, K. Nakayama, K. Sugawara, T. Arakane, Y. Sekiba, A. Takayama, S. Souma, T. Sato, T. Takahashi, Z. Wang, X. Dai, Z. Fang, G. F. Chen, J. L. Luo, N. L. Wang
  • Journal Title: Europhysics Letters Volume: 83 Pages: 47001
  • Peer Reviewed
• [Journal Article] Superconducting Gap and Pseudogap in Iron-Based Layered Superconductor La(O_<1-x>F_x)FeAs (2008)
  • Author(s): T. Sato, K. Nakayama, Y. Sekiba, T. Arakane, K. Terashima, S. Souma, T. Takahashi, Y. Kamihara, M. Hirano, H. Hosono
  • Journal Title: J. Phys. Soc. Jpn. Volume: 77(Suppl.c) Pages: 55-68
  • Peer Reviewed
• [Journal Article] Fermi arc in the superconducting state of impurity-doped Bi_2Sr_2CaCu_2O_8 (2008)
  • Author(s): T. Sato, K. Terashima, K. Nakayama, S. Souma, T. Takahashi, T. Yamamoto, K. Kadowaki
  • Journal Title: Phys. Rev. Volume: B78 Pages: R100502
  • Peer Reviewed
• [Journal Article] Direct evidence for hidden one-dimensional Fermi surface of hexagonal K_<0.25>WO_3 (2008)
  • Author(s): S. Raj, T. Sato, S. Souma, T. Takahashi, D. D. Sarma, Priya Mahadevan, J. C. Campuzano, M. Greenblatt, W. H. McCarroll
  • Journal Title: Phys. Rev. B Volume: 77 Pages: 245120
  • Peer Reviewed
• [Presentation] 高分解能光電子分光でみる強相関微細電子構造 (2011)
  • Author(s): 相馬清吾
  • Organizer: 日本物理学会(第65回年次大会)
  • Place of Presentation: 岡山大学
  • Year and Date: 2011-03-21
• [Presentation] 高分解能光電子分光でみる強相関微細電子構造 (2011)
  • Author(s): Seigo Souma
  • Organizer: The 14^<th> Hiroshima international Symposium on Synchrotron Radiation
  • Place of Presentation: 広島大学
  • Year and Date: 2011-03-05
• [Presentation] Spin-resolved ultrahigh-resolution ARPES study of Rashba effect on semimetal surface (2011)
  • Author(s): Seigo Souma
  • Organizer: The 1^<st> GCOE international Symposium
  • Place of Presentation: 東北大学
  • Year and Date: 2011-02-19
• [Presentation] Ultrahigh-resolution spin-resolved ARPES of novel low-dimensional systems (2010)
  • Author(s): Seigo Souma
  • Organizer: Electronic, transport, and optical properties of low-dimensional systems (WS10-ETOLDs)
  • Place of Presentation: バレンシア, スペイン
  • Year and Date: 2010-05-31
• [Presentation] バルク敏感スピン分解超高分解能光電子分光装置の開発と強相関化合物の電子構造研究 (2009)
  • Author(s): 相馬清吾
  • Organizer: 術領域研究「重い電子系の形成と秩序化」ワークショップ
  • Place of Presentation: 岡山大学
  • Year and Date: 2009-12-26
• [Presentation] Development of bulk-sensitive spin-resolved ultrahigh-resolution photoemission spectrometer (2009)
  • Author(s): Seigo Souma
  • Organizer: LEPES2009 (UVSOR Workshop on Low-Energy Photoemission of Solids using Synchrotron Radiation)
  • Place of Presentation: UVSOR, 岡崎
  • Year and Date: 2009-10-04
• [Presentation] 次元In鎖の金属絶縁体転移の起源: 角度分解光電子分光 (2008)
  • Author(s): 相馬清吾
  • Organizer: 第一回界面科学研究会
  • Place of Presentation: 岡山大学
  • Year and Date: 2008-12-19
• [Presentation] 鉄ニクタイド超伝導体の高分解能角度分解光電子分光 (2008)
  • Author(s): 相馬清吾
  • Organizer: PF研究会「高分解能角度分解光電子分光研究と将来展望」
  • Place of Presentation: 高エネルギー加速器研究機構(つくば)
  • Year and Date: 2008-12-18
• [Presentation] High-resolutions ARPES of novel superconductors (2008)
  • Author(s): Seigo Souma
  • Organizer: Fudan-Tohoku workshop
  • Place of Presentation: 複旦大学, 上海
  • Year and Date: 2008-11-12