Small-to-large Fermi surface fluctuations in heavy fermion systems II: Unconventional superconductivity

How unconventional superconductivity develops from quantum critical metals is a central question in strongly correlated systems. In the studies of antiferromagnetic heavy fermion metals, the notion of Kondo destruction quantum critical point, at which a sharp large-to-small Fermi surface reconstruction appears, has been developed [1]. Here, we demonstrate unconventional superconductivity developing from Fermi surface fluctuations in the Anderson lattice model, in the first analysis based on the cluster-EDMFT approach [2]. For both Kondo-destruction and SDWr quantum criticality, we find that the superconducting transition temperature is exceptionally high relative to the effective Fermi temperature, reaching several percent of the bare Kondo temperature scale [3]. Our results provide a natural understanding of the enigmatic superconductivity in a host of heavy-fermion metals. Implications will be discussed for other classes of strongly correlated systems with superconductivity developing from Fermi-surface fluctuations.

[1] S. Paschen & Q. Si, Nat. Rev. Phys. 3, 9 (2021); S. Kirchner et al, Rev. Mod. Phys. 92, 011002 (2020); Q. Si et al, Nature 413, 804 (2001)

[2] J. Pixley et al, PRB 91, 125127 (2015).

[3] H. Hu, et al., arXiv:2109.13224 (2021).