Fermi Surface Nesting with Heavy Quasiparticles in the Locally Noncentrosymmetric Superconductor CeRh_(2)As_(2)  

作　　者：Yi Wu Yongjun Zhang Sailong Ju Yong Hu Yanen Huang Yanan Zhang Huali Zhang Hao Zheng Guowei Yang Evrard-Ouicem Eljaouhari Baopeng Song Nicholas C.Plumb Frank Steglich Ming Shi Gertrud Zwicknagl Chao Cao Huiqiu Yuan Yang Liu 

机构地区：[1]Center for Correlated Matter and School of Physics,Zhejiang University,Hangzhou 310058,China [2]Institute for Advanced Materials,Hubei Normal University,Huangshi 435002,China [3]Swiss Light Source,Paul Scherrer Institut,CH-5232 Villigen PSI,Switzerland [4]Institut for Mathematische Physik,38106 Braunschweig,Germany [5]Max Planck Institute for Chemical Physics of Solids,01187 Dresden,Germany [6]Collaborative Innovation Center of Advanced Microstructures,Nanjing University,Nanjing 210093,China [7]State Key Laboratory of Silicon Materials,Zhejiang University,Hangzhou 310058,China

出　　处：《Chinese Physics Letters》2024年第9期107-121,共15页中国物理快报（英文版）

基　　金：supported by the National Key R&D Program of China(Grant Nos.2022YFA140220 and 2023YFA1406303);the State Key Project of Zhejiang Province(Grant No.LZ22A040007);the National Natural Science Foundation of China(Grant Nos.U23A20580,12174331,12204159,and 12274364);the Key R&D Program of Zhejiang Province,China(Grant No.2021C01002);the Bridging Grant(Grant No.BG11-072020)with China,Japan,South Korea and ASEAN region funded by the Swiss State Secretariat for Education,Research and Innovation。

摘　　要：The locally noncentrosymmetric heavy fermion superconductor CeRh_(2)As_(2) has attracted considerable interests due to its rich superconducting phases,accompanied by possible quadrupole density wave and pronounced antiferromagnetic excitations.To understand the underlying physics,here we report measurements from highresolution angle-resolved photoemission.Our results reveal fine splittings of the conduction bands related to the locally noncentrosymmetric structure,as well as a quasi-two-dimensional Fermi surface(FS)with strong 4f contributions.The FS shows signs of nesting with an in-plane vector q_(1)=(π/α,π/α),which is facilitated by the heavy bands nearˉ𝑋arising from the characteristic conduction-X hybridization.The FS nesting provides a natural explanation for the observed antiferromagnetic spin fluctuations at(π/α,π/α),which might be the driving force for its unconventional superconductivity.Our experimental results can be reasonably explained by density functional theory plus dynamical mean field theory calculations,which can capture the strong correlation effects.Our study not only provides spectroscopic signature of the key factors underlying the field-induced superconducting transition,but also uncovers the critical role of FS nesting and lattice Kondo effect in the underlying magnetic fluctuations.

关 键 词：SYMMETRIC FERMI conduction 

分 类 号：O469[理学—凝聚态物理]