Title: colloquium: Advanced Film Techniques for High-Tc Superconductors

Speaker: Jin Kui，Institute of Physics, Chinese Academy of Sciences

Time: 4:00 pm, Mar.14th，2024

Venue: Zheng Yutong Lecture Hall

Abstract: In this talk, I would like to briefly share with you our recent work on both physics and applications of High-Tc superconductors via advanced film techniques. For a cuprate system La2-xCexCuO4, we developed advanced high-throughput techniques and used a combinatorial library to map how superconducting properties and normal-state properties of the superconductor evolve with minute compositional variation (~10-4). A scaling relation between the superconducting transition temperature (Tc) and the slope of the T-linear resistivity (A1) was disclosed for the first time, that is, Tc ~ A11/2[1]. For another system FeSe, we achieved continuous evolution of superconductivity in ion-gated FeSe film via electric-field gating technique integrated with two-coil mutual inductance and electrical transport property measurements. Such relationship between Tc and A1 is also at work, yet different techniques were employed to tune the superconductivity minutely [2]. This unexpected universal scale indicates that there is perhaps a common origin of superconductivity in unconventional superconductors. I will also present other interesting scaling relations in overdoped cuprates and preliminary data on the phase diagram of Fe(Se,Te) combinatorial films [3].

References

[1] J. Yuan et al. “Scaling of the strange-metal scattering in unconventional superconductors,” Nature, 602, 431 (2022)

[2] X.J. Jiang et al. “Interplay between superconductivity and the strange-metal state in FeSe,” Nature Phys. 19, 365 (2023)

[3] Z.F. Lin et al. “Phase diagrams on composition-spread FeyTe1-xSex films,” Sci. Bull. 67, 1443 (2022)

Bio: Professor Kui Jin is the director of National Lab for Superconductivity (NLSC) at Institute of Physics, Chinese Academy of Sciences (IOPCAS). He received his Ph.D. from IOPCAS in 2008 and worked as a Research Associate at University of Maryland, College Park until 2012. He then joined IOPCAS and set up his research team in NLSC. His research group is devoted to synthesizing high-quality superconducting films and solving relevant key scientific issues in both physics and applications. Jin and his team established a unique high-throughput superconductivity research paradigm, and successfully disclosed common scaling of the strange metal scattering in high-temperature superconductors. Now he serves as the editorial board member of Physical Review Materials and Science Bulletin. For more information, please view http://combi-film.iphy.ac.cn/en/.