The locally noncentrosymmetric heavy fermion superconductor CeRh2As2 has attracted considerable interests due to its rich superconducting phases,accompanied by possible quadrupole density wave and pronounced antiferro...The locally noncentrosymmetric heavy fermion superconductor CeRh2As2 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 4𝑓contributions.The FS shows signs of nesting with an in-plane vector q1=(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.展开更多
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)+2 种基金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。
文摘The locally noncentrosymmetric heavy fermion superconductor CeRh2As2 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 4𝑓contributions.The FS shows signs of nesting with an in-plane vector q1=(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.
