Quantum criticality from Kondo destruction: Fermi-surface jump to high temperature superconductivity

A prevailing question on quantum criticality is whether and how it goes beyond the Landau framework of order-parameter fluctuations. In the studies of antiferromagnetic heavy fermion metals, the notion of Kondo destruction has been developed to address the issue [1]. A defining characteristic across the Kondo-destruction quantum critical point (QCP) is a sudden transformation between “large” and “small” Fermi surface. Here, we focus on the QCP in the Kondo lattice and related models with continuous spin symmetry [2]. A key feature is dynamical Kondo effect, as captured by entanglement properties [2] and by an E/T scaling in singular charge responses at the antiferromagnetic QCP [3,4]. These features set the stage for demonstrating and understanding the emergence of unconventional superconductivity at the Kondo-destruction QCP. We find high temperature superconductivity in the sense that the transition temperature Tc reaches several percentages of the bare effective Fermi temperature scale. We discuss a) the immediate implications of our results for superconductivity in CeRhIn5, CeCu2Si2 and other heavy fermion systems; and b) the larger lessons for superconductivity in other correlated systems that are close to a large-to-small Fermi surface transformation.

*In collaboration with Haoyu Hu, Ang Cai, Zuodong Yu, Stefan Kirchner, Lei Chen, Jed Pixley, Lili Deng and Kevin Ingersent. Work at Rice has been supported by the AFOSR grant # FA9550-21-1-0356, NSF grant # DMR-1920740 and Welch Foundation grant # C-1411.

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

[2] H. Hu, A. Cai, Q. Si, arXiv:2004.04679 (2020).

[3] A. Cai, Z. Yu, H. Hu, S. Kirchner, Q. Si, Phys. Rev. Lett. 124, 027205 (2020); L. J. Zhu, S. Kirchner, Q. Si, A. Georges, Phys. Rev. Lett. 93, 267201 (2004).

[4] L. Prochaska et al, Science 367, 285 (2020).

E-mail for corresponding author: [email protected]