Superconductivity under pressure in a chromium-based kagome metal

• 成果类型: Article
• 署名作者: Liu, Yi; Liu, Zi-Yi; Bao, Jin-Ke; Yang, Peng-Tao; Ji, Liang-Wen; Wu, Si-Qi; Shen, Qin-Xin; Luo, Jun; Yang, Jie; Liu, Ji-Yong; Xu, Chen-Chao; Yang, Wu-Zhang; Chai, Wan-Li; Lu, Jia-Yi; Liu, Chang-Chao; Wang, Bo-Sen; Jiang, Hao; Tao, Qian; Ren, Zhi; Xu, Xiao-Feng; Cao, Chao; Xu, Zhu-An; Zhou, Rui; Cheng, Jin-Guang; Cao, Guang-Han
• 署名单位: Zhejiang University; Zhejiang University of Technology; Chinese Academy of Sciences; Chinese Academy of Sciences; Institute of Physics, CAS; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; Hangzhou Normal University; Hangzhou Normal University; Shanghai University; Shanghai University; Zhejiang University; Westlake University; Xiangtan University; Zhejiang University
• 刊物名称: Nature
• ISSN/ISSBN: 0028-6125
• DOI: 10.1038/s41586-024-07761-x
• 发表日期: 2024-08-29
• 关键词: charge order

摘要

Superconductivity in a highly correlated kagome system has been theoretically proposed for years (refs. 1-5), yet the experimental realization is hard to achieve6,7. The recently discovered vanadium-based kagome materials8, which exhibit both superconductivity9-11 and charge-density-wave orders12-14, are nonmagnetic8,9 and weakly correlated15,16. Thus these materials are unlikely to host the exotic superconductivity theoretically proposed. Here we report the discovery of a chromium-based kagome metal, CsCr3Sb5, which is contrastingly featured with strong electron correlations, frustrated magnetism and characteristic flat bands close to the Fermi level. Under ambient pressure, this kagome metal undergoes a concurrent structural and magnetic phase transition at 55 K, with a stripe-like 4a0 structural modulation. At high pressure, the phase transition evolves into two transitions, possibly associated with charge-density-wave and antiferromagnetic spin-density-wave orderings. These density-wave-like orders are gradually suppressed with pressure and, remarkably, a superconducting dome emerges at 3.65-8.0 GPa. The maximum of the superconducting transition temperature, Tcmax = 6.4 K, appears when the density-wave-like orders are completely suppressed at 4.2 GPa, and the normal state exhibits a non-Fermi-liquid behaviour, reminiscent of unconventional superconductivity and quantum criticality in iron-based superconductors17,18. Our work offers an unprecedented platform for investigating superconductivity in correlated kagome systems. The emergence of superconductivity under pressure is reported in a chromium-based kagome metal, CsCr3Sb5, which has strong electron correlations, frustrated magnetism and characteristic flat bands close to the Fermi level.