Routes to heavy-fermion superconductivity

10th International Conference on Materials and Mechanisms of Superconductivity

Steglich, F.^1 ; Stockert, O.^1 ; Wirth, S.^1 ; Geibel, C.^1 ; Yuan, H.Q.^2 ; Kirchner, S.^1,3 ; Si, Q.^4

Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, 01187 Dresden, Germany^1

Department of Physics and Center for Correlated Matter, Zhejiang University, Hangzhou, Zhejiang 310027, China^2

Max Planck Institute for Physics of Complex Systems, Nöthnitzer Str. 38, 01187 Dresden, Germany^3

Department of Physics and Astronomy, Rice University, Houston, TX 77005, United States^4

关键词: Antiferromagnetics;    De Haas-van Alphen;    Field induced;    Heavy-fermion superconductivity;    Quadrupole moments;    Quantum critical points;    Related compounds;    Superconducting phase;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/449/1/012028/pdf
DOI  :  10.1088/1742-6596/449/1/012028

来源: IOP

【 摘 要 】

Superconductivity in lanthanide- and actinide-based heavy-fermion (HF) metals can have different microscopic origins. Among others, Cooper pair formation based on fluctuations of the valence, of the quadrupole moment or of the spin of the localized 4f/5f shell have been proposed. Spin-fluctuation mediated superconductivity in CeCu2Si2 was demonstrated by inelastic neutron scattering to exist in the vicinity of a spin-density-wave (SDW) quantum critical point (QCP). The isostructural HF compound YbRh2Si2 which is prototypical for a Kondo-breakdown QCP has so far not shown any sign of superconductivity down to T = 10 mK. In contrast, results of de-Haas-van-Alphen experiments by Shishido et al. (J. Phys. Soc. Jpn. 74, 1103 (2005)) suggest superconductivity in CeRhIn5 close to an antiferromagnetic QCP beyond the SDW type, at which the Kondo effect breaks down. For the related compound CeCoIn5 however, a field-induced QCP of SDW type is extrapolated to exist inside the superconducting phase.