Study of multi-dynamics of electronic degrees of freedom in high-Tc cuprate superconductor

2015 Fiscal Year Final Research Report

• Project/Area Number: 23340093
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Condensed matter physics II
• Research Institution: Tohoku University
• Principal Investigator: FUJITA Masaki 東北大学, 金属材料研究所, 教授 (20303894)
• Co-Investigator(Kenkyū-buntansha): YAMASE Hiroyuki 国立研究開発法人物質・材料研究機構, 環境・エネルギー材料部門 超伝導物性ユニット, 主任研究員 (10342867) ; MORI Michiyasu 国立研究開発法人日本原子力研究開発機構, 先端基礎研究センター, 副主任研究員 (30396519) ; ADACHI Tadashi 上智大学, 理工学部, 准教授 (40333843) ; ISHII Kenji 国立研究開発法人日本原子力研究開発機構, 量子ビーム応用研究部門 構造物性研究ユニット, 研究副主任 (40343933)
• Project Period (FY): 2011-04-01 – 2016-03-31
• Keywords: 高温超伝導 / 中性子散乱 / 結晶作成

Outline of Final Research Achievements

This research aims to clarify an existence of complex excitation composed of spin, charge and phonon degrees of freedom in high-Tc cuprate superconductor, with utilizing quantum beams such as neutron, synchrotron X-ray and muon. The hierarchical spin excitation attributed to the localized and itinerant nature of electron was found in the hole-doped system. Furthermore, we clarified an enhancement of spin-phonon coupling by the hole-doping. On the other hand, in the electron-doped system, the evidence of spin-charge coupling was seen in the high-energy excitation. The most important result of this research is that we clarified an existence of electron-hole asymmetry in the spin and charge correlations in cuprate superconductors. The coupling among spin change and phonon is also different in the hole and electron doped systems.

Free Research Field

物性物理