Scaling of the strange-metal scattering in unconventional superconductors

About one decade ago, several groups [1-3] unveiled an intimated correlation between the superconducting transition temperature (T c ) and the slope of the T-linear resistivity (A 1 ). That is, these two quantities increase or decrease simultaneously. Consequently, the question the community has been after is: what connects the strength of superconductivity with electron scattering? To solve this issue, one needs to quantify the relationship between T c and A 1 . However, it turns out to be a great challenge to manipulate external parameters for marked evolution of properties with minute changes. In this talk, I would like to share with you two pieces of our recent work [4,5] and report on the discovery of T c ~ A 1 0.5 relationship in different families of high-temperature superconductors. For a cuprate system La 2-x Ce x CuO 4 , 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 (Δx) with unprecedented resolution and accuracy [4]. We also 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 [5]. Such relationship between T c and A 1 is at work for both systems, yet different techniques were employed to tune the superconductivity minutely. Remarkably, the scaling is seemingly satisfied also in hole-doped cuprate, as well as a class of organic superconductors via pressure tuning. This unexpected universal scale indicates that there is perhaps a common origin of superconductivity in unconventional superconductors.

[1] Cooper et al. Science 323,603 (2009)

[2] Taillefer Annu. Rev. Condens. Matter Phys. 1,51 (2010)

[3] Jin et al. Nature 476,73 (2011)

[4] Yuan et al. Nature 602,431 (2022)

[5] Jiang et al. arXiv2103.06512