• Search Research Projects
  • Search Researchers
  • How to Use
  1. Back to previous page

Correlation between charge order and superconductivity in La-based intermetallic compounds

Research Project

Project/Area Number 22K14006
Research Category

Grant-in-Aid for Early-Career Scientists

Allocation TypeMulti-year Fund
Review Section Basic Section 13030:Magnetism, superconductivity and strongly correlated systems-related
Research InstitutionOkayama University

Principal Investigator

Akiba Kazuto  岡山大学, 環境生命自然科学学域, 助教 (60824026)

Project Period (FY) 2022-04-01 – 2024-03-31
Project Status Completed (Fiscal Year 2023)
Budget Amount *help
¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000)
Fiscal Year 2023: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
Fiscal Year 2022: ¥2,730,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥630,000)
Keywords超伝導 / 電荷密度波 / 圧力 / Fermi面 / 量子臨界点 / 第一原理計算
Outline of Research at the Start

電荷秩序と超伝導の協奏現象に近年注目が集まっているが、外部から両方の物性を都合よく制御できる系は少なく未解明な点が多い。本研究では3つのLa系層状金属間化合物において圧力を制御パラメータとした系統的実験研究を行い、CDWと超伝導の相関関係を明らかにする。申請者独自の圧力セル回転機構を用いた量子振動測定により、これまで困難であった圧力下電子状態の正確な決定が可能である。この基盤的理解に基づいてCDW・超伝導共存状態が異なる3つの物質の相図と圧力下物性の比較対照を行い、CDWの臨界圧力近傍でTcの向上を引き起こす電子状態の条件を解明する。

Outline of Final Research Achievements

In this study, we aimed to understand the enhancement mechanism of superconductivity at a critical point of charge density wave (CDW) state. We clarified for the first time that LaAgSb2 hosts both CDW and superconductivity at ambient pressure, and the superconducting transition temperature (Tc) is enhanced only near the CDW critical pressure. Considering the superconducting properties of related materials, we suggest that the realization of CDW and superconductivity in an identical Fermi surface is an important factor for the nontrivial enhancement of Tc.

Academic Significance and Societal Importance of the Research Achievements

これまで磁気秩序の量子臨界点における非従来型超伝導発現の可能性については多くの物質での先行研究が見られる一方で、電荷秩序の臨界点と超伝導の関係性に関する知見は乏しく十分な理解が得られているとは言い難い。その中で本研究は、LaAgSb2およびその類縁物質が圧力を調整パラメータとしてCDWと超伝導を制御できる好都合な舞台であることを示した。また第一原理計算を用いて実験結果を解釈することで、LaAgSb2で超伝導に寄与するFermi面を確定するとともに従来のフォノン媒介機構だけでは実験で観測されたTcの増強を説明できないことを明確にした。

Report

(3 results)
  • 2023 Annual Research Report   Final Research Report ( PDF )
  • 2022 Research-status Report
  • Research Products

    (14 results)

All 2023 2022 Other

All Journal Article (7 results) (of which Peer Reviewed: 7 results,  Open Access: 5 results) Presentation (6 results) (of which Invited: 1 results) Remarks (1 results)

  • [Journal Article] Phonon-mediated superconductivity in the Sb square-net compound LaCuSb22023

    • Author(s)
      Akiba Kazuto、Kobayashi Tatsuo C.
    • Journal Title

      Physical Review B

      Volume: 107 Issue: 24 Pages: 245117-245117

    • DOI

      10.1103/physrevb.107.245117

    • Related Report
      2023 Annual Research Report
    • Peer Reviewed / Open Access
  • [Journal Article] Superconductivity in a ferroelectric-like topological semimetal SrAuBi2023

    • Author(s)
      Takahashi Hidefumi、Sasaki Tomohiro、Nakano Akitoshi、Akiba Kazuto、Takahashi Masayuki、Mayo Alex H.、Onose Masaho、Kobayashi Tatsuo C.、Ishiwata Shintaro
    • Journal Title

      npj Quantum Materials

      Volume: 8 Issue: 1 Pages: 77-77

    • DOI

      10.1038/s41535-023-00612-4

    • Related Report
      2023 Annual Research Report
    • Peer Reviewed / Open Access
  • [Journal Article] Superconductivity in a Magnetic Rashba Semimetal EuAuBi2023

    • Author(s)
      Takahashi Hidefumi、Akiba Kazuto、Takahashi Masayuki、Mayo Alex H.、Ochi Masayuki、Kobayashi Tatsuo C.、Ishiwata Shintaro
    • Journal Title

      Journal of the Physical Society of Japan

      Volume: 92 Issue: 1 Pages: 0137011-5

    • DOI

      10.7566/jpsj.92.013701

    • Related Report
      2022 Research-status Report
    • Peer Reviewed / Open Access
  • [Journal Article] Spin-orbit-derived giant magnetoresistance in a layered magnetic semiconductor <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>AgCrSe</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:math>2022

    • Author(s)
      Takahashi Hidefumi、Akiba Tomoki、Mayo Alex Hiro、Akiba Kazuto、Miyake Atsushi、Tokunaga Masashi、Mori Hitoshi、Arita Ryotaro、Ishiwata Shintaro
    • Journal Title

      Physical Review Materials

      Volume: 6 Issue: 5 Pages: 054602-054602

    • DOI

      10.1103/physrevmaterials.6.054602

    • Related Report
      2022 Research-status Report
    • Peer Reviewed
  • [Journal Article] Site Split of Antiferromagnetic α-Mn Revealed by <sup>55</sup>Mn Nuclear Magnetic Resonance2022

    • Author(s)
      Manago Masahiro、Motoyama Gaku、Nishigori Shijo、Fujiwara Kenji、Kinjo Katsuki、Kitagawa Shunsaku、Ishida Kenji、Akiba Kazuto、Araki Shingo、Kobayashi Tatsuo C.、Harima Hisatomo
    • Journal Title

      Journal of the Physical Society of Japan

      Volume: 91 Issue: 11 Pages: 113701-113701

    • DOI

      10.7566/jpsj.91.113701

    • Related Report
      2022 Research-status Report
    • Peer Reviewed
  • [Journal Article] Topological Phase Transitions and Critical Phenomena Associated with Unwinding of Spin Crystals by High Magnetic Fields2022

    • Author(s)
      Kanazawa Naoya、Fujishiro Yukako、Akiba Kazuto、Kurihara Ryosuke、Mitamura Hiroyuki、Miyake Atsushi、Matsuo Akira、Kindo Koichi、Tokunaga Masashi、Tokura Yoshinori
    • Journal Title

      Journal of the Physical Society of Japan

      Volume: 91 Issue: 10 Pages: 101002-101002

    • DOI

      10.7566/jpsj.91.101002

    • Related Report
      2022 Research-status Report
    • Peer Reviewed / Open Access
  • [Journal Article] Observation of superconductivity and its enhancement at the charge density wave critical point in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>LaAgSb</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:math>2022

    • Author(s)
      Akiba Kazuto、Umeshita Nobuaki、Kobayashi Tatsuo C.
    • Journal Title

      Physical Review B

      Volume: 106 Issue: 16

    • DOI

      10.1103/physrevb.106.l161113

    • Related Report
      2022 Research-status Report
    • Peer Reviewed / Open Access
  • [Presentation] CeAgSb2の圧力下交流比熱測定2023

    • Author(s)
      秋葉和人, 小林達生
    • Organizer
      日本物理学会 第78回年次大会
    • Related Report
      2023 Annual Research Report
  • [Presentation] 圧力による連続制御と極限環境下精密測定で拓く新奇電子物性2023

    • Author(s)
      秋葉和人
    • Organizer
      第64回高圧討論会
    • Related Report
      2023 Annual Research Report
    • Invited
  • [Presentation] 圧力下のLaAuSb2における電荷密度波と超伝導の相関関係2023

    • Author(s)
      秋葉和人, 小林達生
    • Organizer
      日本物理学会 2023年春季大会
    • Related Report
      2022 Research-status Report
  • [Presentation] Superconductivity and its enhancement at the charge-density-wave critical point in LaAgSb22022

    • Author(s)
      Kazuto Akiba
    • Organizer
      Progress in Superconductivity Research; RIIS Mini-Workshop
    • Related Report
      2022 Research-status Report
  • [Presentation] LaAgSb2の圧力誘起CDW臨界点における電荷揺らぎ超伝導の可能性2022

    • Author(s)
      秋葉和人, 梅下暢朗, 小林達生
    • Organizer
      第1回 アシンメトリ量子研究会
    • Related Report
      2022 Research-status Report
  • [Presentation] LaAgSb2の圧力誘起CDW臨界点における超伝導の増強現象2022

    • Author(s)
      秋葉和人, 梅下暢朗, 小林達生
    • Organizer
      日本物理学会 2022年秋季大会
    • Related Report
      2022 Research-status Report
  • [Remarks] 秋葉和人ホームページ

    • URL

      http://www.physics.okayama-u.ac.jp/~akiba

    • Related Report
      2023 Annual Research Report

URL: 

Published: 2022-04-19   Modified: 2025-01-30  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi