时间: 2024年9月26日（周四）上午10:00-11:30

Time: 10:00-11:30, Thursday, September 26^th, 2024

主持人: 西湖大学理学院吴颉博士

Host: Dr. Jie Wu, PI of School of Science, Westlake University

地址：西湖大学云谷校区E10-211教室

Venue: Room E10-211, Yungu Campus

语言：中文

Language：Chinese

程金光教授

中国科学院物理研究所

Prof. Jinguang Cheng

Institute of Physics, Chinese Academy of Sciences

主讲人/Speaker:

Jinguang Cheng is a professor at the Institute of Physics, Chinese Academy of Sciences (IOPCAS). He obtained his Ph.D. in Materials Science from the University of Texas at Austin in 2010. Following two-year postdoctoral research at Austin, he joined IOPCAS and became the ground leader of EX6 in the Laboratory of Extreme Conditions Physics since 2014. His research interest focuses on the explorations of novel quantum materials and phenomena under high-pressure extreme conditions. He has published over 240 peer-reviewed journal papers and received the Sir Martin Wood China Prize in 2016.

讲座摘要/Abstract:

Following the discovery of superconductivity in the infinite-layer Nd_1-xSr_xNiO₂ thin films at ambient pressure [1], the recent report of high-T_c superconductivity in the bilayer La₃Ni₂O₇ [2]and trilayer La₄Ni₃O₁₀ [3] at high pressures has further expanded the family of nickelate superconductors. These breakthroughs marked the coming of “Nickel Age” of high-temperature superconductors. Despite of some important progresses [4, 5], there remain many open issues for the bilayer La₃Ni₂O₇ showing the highest onset of T_c ~80 K at pressures above 14 GPa [2]. For example, obvious diamagnetic signals, the other hallmark of superconductors, are still lacking owing to the filamentary nature with low superconducting volume fraction [6]. In this talk, I will first give an overview on recent experimental progresses and summarize the current status and open issues about the nickelates superconductors. Then, I will present our recent high-pressure results on the rare-earth-substituted La_3-xR_xNi₂O₇ (R = Pr, Nd, Tb) polycrystalline samples. For La₂PrNi₂O₇,in addition to achieve zero resistivity below T_c^zero = 60 K at 18-20 GPa, we confirmed the bulk nature of high-T_c superconductivity by detecting clear diamagnetic signals below ~75 K in the ac magnetic susceptibility [7]. In addition, we have revealed distinct effects of chemical versus physical pressures on the structural transition of bilayer nickelates [8]. Our results not only resolve some existing controversies but also illuminate directions for exploring bulk high-T_c superconductivity in the bilayer nickelates.

[1] D. F. Li, K. Lee, B. Y. Wang, et al., Nature572, 624 (2019)

[2] H. L. Sun, M. W. Huo, X. W. Hu, et al., Nature621, 493 (2023)

[3] Y. H. Zhu, D. Peng, E. K. Zhang, et al., Nature631, 531 (2024)

[4] G. Wang, N. N. Wang, X. L. Shen, et al., Phys. Rev. X14, 011040 (2024)

[5] Y. N. Zhang, D. J. Sun, Y. N. Huang, et al., Nature Phys.20, 1269 (2024)

[6] Y. Z. Zhou, J. Guo, S. Cai, et al., ArXiv: 2311.12361 (2023)

[7] N. N. Wang, G. Wang, X. L. Shen, et al., ArXiv: 2407.05681; Nature (Accepted) (2024)

[8] G. Wang, N. N. Wang, T. L. Lu, et al., ArXiv: 2408.09421 (2024)

讲座联系人/Contact:

理学院，钟梦真，邮箱：zhongmengzhen@westlake.edu.cn

School of Science, Mengzhen Zhong, Email: zhongmengzhen@westlake.edu.cn