Search for novel electronic states of superconductivity in strongly electron systems by tunneling spectroscopy under pressure with the imaging

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K03733
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 13030:Magnetism, superconductivity and strongly correlated systems-related
• Research Institution: Muroran Institute of Technology (2021); Hokkaido University (2019-2020)
• Principal Investigator: KUROSAWA Tohru 室蘭工業大学, 大学院工学研究科, 准教授 (10615420)
• Co-Investigator(Kenkyū-buntansha): 桃野 直樹 室蘭工業大学, 大学院工学研究科, 教授 (00261280)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 銅酸化物高温超伝導体 / ペア密度波 / 走査トンネル顕微鏡 / 走査トンネル分光法 / 電荷秩序

Outline of Final Research Achievements

To investigate the nature of the pair density wave in Bi2212, STM/STS measurements were performed. In the underdoped regime, a period of the pair density wave is of about 4 times lattice constant which is consistent with the previous result. On the other hand, in the overdoped regime, the period of the pair density wave is of about 5 times lattice constant. This tendency would be similar to that of the electronic charge order in the cuprates. This result indicates that the pair density wave would be closely related with the charge order. The pair density wave was clearly observed at an energy whose size is scale with superconducting transition temperature.

Free Research Field

固体物理

Academic Significance and Societal Importance of the Research Achievements

超伝導を担うクーパー対の密度が空間的に変調することで起こるペア密度波の理解は、超伝導の発現機構を考えるうえで重要な役割を担っている。本研究では、ペア密度波が超伝導転移温度より高温で形成される電荷秩序と密接な関係があることを示唆する結果が得られた。今後、電荷秩序とペア密度波をコントロールすることで、より高温で超伝導を実現することや新規デバイスへの応用が期待される。