Elucidation of the symmetry of superconducting gap of topological superconductor CuxBi2Se3 and other novel materials

2013 Fiscal Year Final Research Report

• Project/Area Number: 24740237
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Condensed matter physics II
• Research Institution: Osaka University
• Principal Investigator: SASAKI Satoshi 大阪大学, 産業科学研究所, 助教 (00540105)
• Project Period (FY): 2012-04-01 – 2014-03-31
• Keywords: トポロジカル絶縁体ヘテロ構造物質 / 超伝導トポロジカル結晶絶縁体 / 超伝導トポロジカル絶縁体

Research Abstract

Two new superconductors with time-reversal invariance similar to a superconducting topological insulator CuxBi2Se3 have been discovered: one of them is a superconducting In-doped topological crystalline insulator Sn1-xInxTe; the other is a superconductor Cux(PbSe)5(Bi2Se3)6 synthesized by intercalating Cu into a topological insulator heterostructure consisting of Bi2Se3 (topological insulator) and PbSe (ordinary insulator). The point-contact spectroscopy and specific heat measurements allowed us to elucidate the symmetry of the superconducting gaps in these materials. Based on the revealed properties we proposed Sn1-xInxTe and Cux(PbSe)5(Bi2Se3)6 as candidate materials that can build a platform for the study of topological superconductivity, contributing to the development of the relevant field.

Research Products

• [Journal Article] Topological surface transport in epitaxial SnTe thin films grown on Bi_2Se_3 (2014)
  • Author(s): A. A. Taskin, Fan Yang, Satoshi Sasaki, Kouji Segawa, Yoichi Ando
  • Journal Title: Physical Review B Volume: 89 Pages: 121302(R)-(1-5)
  • DOI: 10.1103/PhysRevB.89.121302
  • Peer Reviewed
• [Journal Article] Unusual nature of fully gapped superconductivity in In-doped SnTe (2013)
  • Author(s): Mario Novak, Satoshi Sasaki, Markus Kriener, Kouji Segawa, Yoichi Ando
  • Journal Title: Physical Review B Volume: 88 Pages: 140502(R)-(1-5)
  • DOI: 10.1103/PhysRevB.88.140502
  • Peer Reviewed
• [Journal Article] Anomalous Dressing of Dirac Fermions in the Topological Surface State of Bi_2Se_3, Bi_2Te_3, and Cu-Doped Bi_2Se_3 (2013)
  • Author(s): Takeshi Kondo, Y. Nakashima, Y. Ota, Y. Ishida, W. Malaeb, K. Okazaki, S. Shin, M. Kriener, Satoshi Sasaki, Kouji Segawa, Yoichi Ando
  • Journal Title: Physical Review Letter Volume: 110 Pages: 217601-(1-5)
  • DOI: 10.1103/PhysRevLett.110.217601
  • Peer Reviewed
• [Journal Article] Fermiology of the Strongly Spin-Orbit Coupled Superconductor Sn_<1->xIn_xTe : Implications for Topological Superconductivity (2013)
  • Author(s): T. Sato, Y. Tanaka, K. Nakayama, S. Souma, T. Takahashi, S. Sasaki, Z. Ren, A. A. Taskin, Kouji Segawa, Yoichi Ando
  • Journal Title: Physical Review Letter Volume: 110 Pages: 206804-(1-5)
  • DOI: 10.1103/PhysRevLett.110.206804
  • Peer Reviewed
• [Journal Article] トポロジカル超伝導体実証への道 : ソフトポイントコンタクト分光法の開発 (2013)
  • Author(s): 佐々木聡、クリーナーマルクス、瀬川耕司、安藤陽一
  • Journal Title: 超伝導科学技術研究会FSST NEWS Volume: No.138 Pages: 17-20
  • URL: http://www.sntt.or.jp/~fsst/fsstnews2013.html
• [Journal Article] Odd-Parity Pairing and Topological Superconductivity in a Strongly Spin-Orbit Coupled Semiconductor (2012)
  • Author(s): Satoshi Sasaki, Zhi Ren, A. A. Taskin, Kouji Segawa, Liang Fu, Yoichi Ando
  • Journal Title: Physical Review Letter Volume: 109 Pages: 217004-(1-5)
  • DOI: 10.1103/PhysRevLett.109.217004
  • Peer Reviewed
• [Journal Article] Anomalous suppression of the superfluid density in the Cu_xBi_2Se_3 superconductor upon progressive Cu intercalation (2012)
  • Author(s): M. Kriener, Kouji Segawa, Satoshi Sasaki, Yoichi Ando
  • Journal Title: Physical Review B Volume: 86 Pages: 180505(R)-(1-5)
  • DOI: 10.1103/PhysRevB.86.180505
  • Peer Reviewed
• [Journal Article] Achieving Surface Quantum Oscillations in Topological Insulator Thin Films of Bi_2Se_3 (2012)
  • Author(s): A. A. Taskin, Satoshi Sasaki, Kouji Segawa, Yoichi Ando
  • Journal Title: Advanced Materials Volume: 24 Pages: 5581-5585
  • DOI: 10.1002/adma.201201827
  • Peer Reviewed
• [Journal Article] Manifestation of Topological Protection in Transport Properties of Epitaxial Bi_2Se_3 Thin Films (2012)
  • Author(s): A. A. Taskin, Satoshi Sasaki, Kouji Segawa, Yoichi Ando
  • Journal Title: Physical Review Letter Volume: 109 Pages: 066803-(1-5)
  • DOI: 10.1103/PhysRevLett.109.066803
  • Peer Reviewed
• [Presentation] Superconducting doped topological insulators (2014)
  • Author(s): Satoshi Sasaki
  • Organizer: The 5th Science Research Center for Topological Matter Winter Workshop
  • Place of Presentation: Yongpyong Resort (Republic of Korea)
  • Year and Date: 2014-02-06
  • Invited
• [Presentation] 超伝導トポロジカル絶縁体のバルクトポロジカル超伝導性、新学術領域研究・対称性の破れた凝縮系におけるトポロジカル量子現象 (2013)
  • Author(s): 佐々木聡, M. Novak, M. Kriener,瀬川耕司,安藤陽一
  • Organizer: 第4回領域研究会「トポロジカル超伝導・超流動」
  • Place of Presentation: 名古屋大学(愛知県名古屋市)
  • Year and Date: 2013-12-19
  • Invited
• [Presentation] Conductance Spectroscopy on Superconducting Topological Insulator Families (2013)
  • Author(s): Satoshi Sasaki, A. A. Taskin, K. Segawa, Y. Ando
  • Organizer: International Workshop for Young Researchers on Topological Quantum Phenomena in Condensed Matter with Broken Symmetries 2013
  • Place of Presentation: カルチャーリゾートフェストーネ(沖縄県宜野湾市)
  • Year and Date: 2013-10-23
  • Invited
• [Presentation] Phase diagram of Sn_<1->xIn_xTe - a Topological Superconductor candidate (2013)
  • Author(s): M. Novak, Satoshi Sasaki, M. Kriener, K. Segawa, Y. Ando
  • Organizer: International Workshop for Young Researchers on Topological Quantum Phenomena in Condensed Matter with Broken Symmetries 2013
  • Place of Presentation: カルチャーリゾートフェストーネ(沖縄県宜野湾市)
  • Year and Date: 2013-10-23
• [Presentation] 超伝導Tl_5Te_3のポイントコンタクト分光 (2013)
  • Author(s): 佐々木聡、鳥羽俊伸、瀬川耕司、安藤陽一
  • Organizer: 日本物理学会2013年秋季大会
  • Place of Presentation: 徳島大学(徳島県徳島市)
  • Year and Date: 2013-09-27
• [Presentation] Experimental efforts to realize time-reversal invariant topological superconductors (2013)
  • Author(s): Satoshi Sasaki, A. A. Taskin, K. Segawa, Y. Ando
  • Organizer: International Symposium on Quantum Fluids and Solids(QFS2013)
  • Place of Presentation: くにびきメッセ(島根県松江市)
  • Year and Date: 2013-08-05
  • Invited
• [Presentation] レーザー励起型角度分解光電子分光で観察したカリウム蒸着により変化するトポロジカル絶縁体の表面電子状態 (2013)
  • Author(s): 中島祐貴,近藤猛,石田行章, Walid Malaeb,渡部俊太郎, Cuangtian Chen, Markus Kriener,佐々木聡,瀬川耕司,安藤陽一,辛埴
  • Organizer: 日本物理学会第68回年次大会
  • Place of Presentation: 広島大学東広島キャンパス(広島県東広島市)
  • Year and Date: 2013-03-28
• [Presentation] ドープされたトポロジカル結晶絶縁体Sn1-xInxTeの超電導特性 (2013)
  • Author(s): 佐々木聡,任之, A. A. Taskin,瀬川耕司, L. Fu,安藤陽一
  • Organizer: 日本物理学会第68回年次大会
  • Place of Presentation: 広島大学東広島キャンパス(広島県東広島市)
  • Year and Date: 2013-03-28
• [Presentation] Search for topological superconductivity in superconducting topological insulators (2013)
  • Author(s): Satoshi Sasaki
  • Organizer: American Physical Society March Meeting
  • Place of Presentation: Baltimore (Washington D.C., U.S.A)
  • Year and Date: 2013-03-18
  • Invited
• [Presentation] 超伝導トポロジカル絶縁体のトポロジカル超伝導性、新学術領域研究・対称性の破れた凝縮系におけるトポロジカル量子現象 (2012)
  • Author(s): 佐々木聡
  • Organizer: 第10回集中連携研究会「トポロジカル超伝導・超流動」
  • Place of Presentation: 大阪大学産業科学研究所(大阪府茨木市)
  • Year and Date: 2012-12-13
  • Invited
• [Presentation] 超伝導トポロジカル絶縁体の物性研究 (2012)
  • Author(s): 佐々木聡
  • Organizer: 物性セミナー
  • Place of Presentation: 東京大学駒場キャンパス(東京都目黒区)
  • Year and Date: 2012-11-16
  • Invited
• [Presentation] 新奇な超伝導体候補物質TlドープPbTeの単結晶作製 (2012)
  • Author(s): 上山卓巳,佐々木聡, A. A. Taskin,瀬川耕司,安藤陽一
  • Organizer: 日本物理学会2012年秋季大会
  • Place of Presentation: 横浜国立大学常盤台キャンパス(神奈川県横浜市
  • Year and Date: 2012-09-20
• [Presentation] コバルト膜を蒸着したトポロジカル絶縁体バルク単結晶の輸送特性 (2012)
  • Author(s): 江藤数馬,佐々木聡, Zhi Ren,瀬川耕司,安藤陽一
  • Organizer: 日本物理学会2012年秋季大会
  • Place of Presentation: 横浜国立大学常盤台キャンパス(神奈川県横浜市
  • Year and Date: 2012-09-20
• [Presentation] MBE Growth of Topological Insulators (2012)
  • Author(s): A. A. Taskin, Satoshi Sasaki, K. Segawa, Y. Ando
  • Organizer: 日本物理学会2012年秋季大会
  • Place of Presentation: 横浜国立大学常盤台キャンパス(神奈川県横浜市
  • Year and Date: 2012-09-19
• [Presentation] Soft point-contact spectroscopy of Cu_xBi_2Se_3 (2012)
  • Author(s): Satoshi Sasaki, M. Kriener, K. Segawa, K. Yada, Y. Tanaka, M. Sato, Y. Ando
  • Organizer: Gordon Research Conference the 2012 correlated electron systems
  • Place of Presentation: South Hadley (Massachusetts, U.S.A.)
  • Year and Date: 2012-06-27
• [Presentation] Soft point-contact spectroscopy of Cu_xBi_2Se_3 (2012)
  • Author(s): Satoshi Sasaki, M. Kriener, K. Segawa, Y. Ando
  • Organizer: International Conference on Topological Quantum Phenomena (TQP2012)
  • Place of Presentation: 名古屋大学(愛知県名古屋市)
  • Year and Date: 2012-05-19
• [Presentation] Small superfluid density in Cu_xBi_2Se_3 (2012)
  • Author(s): M. Kriener, S. Segawa, Satoshi Sasaki, Y. Ando
  • Organizer: International Conference on Topological Quantum Phenomena (TQP2012)
  • Place of Presentation: 名古屋大学(愛知県名古屋市)
  • Year and Date: 2012-05-19
• [Presentation] Molecular Beam Epitaxial Growth of Topological Insulators on Insulating Substrates (2012)
  • Author(s): A. Taskin, Satoshi Sasaki, K. Segawa, Y. Ando
  • Organizer: International Conference on Topological Quantum Phenomena (TQP2012)
  • Place of Presentation: 名古屋大学(愛知県名古屋市)
  • Year and Date: 2012-05-17
• [Remarks]
  • URL: http://www.sanken.osaka-u.ac.jp/~sasaki/