Quantum Entanglement Characterization of Kondo-destruction Quantum Critical Points

Heavy fermion metals are made of a lattice of local moments undergoing Kondo effect. A

Kondo-destruction Quantum Critical Point (QCP) separates the Kondo and RKKY

dominated phases. The suppression of the Kondo effect is signified by a jump from “large”

to “small” Fermi surface across the QCP [1,2]. While the static amplitude for the Kondo

singlet vanishes on this side of the QCP, there are non-zero Kondo correlations usually

called dynamical Kondo effect[3,4]. Entanglement is one way to probe the local moment

dynamics in these strongly-correlated systems[5,6]. We consider Kondo destruction QCP

of both the Bose-Fermi Kondo model and the Kondo lattice, and calculate entanglement

entropy and mutual information to characterize the competition of the RKKY, Kondo

interactions across the QCP and the dynamical Kondo effect.

[1] H. Hu et al., arXiv:2210.14183. Q. Si et al., Nature 413, 804–808 (2001).

[2] S. Paschen and Q. Si, Nat. Phys. Rev. 3, 9 (2021). S. Kirchner et al., Rev. Mod. Phys.

92, 011002 (2020).

[3] A. Cai et al., Phys. Rev. Lett. 124, 027205 (2020).

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

[5] H. Hu et al., arXiv:2004.04679 (2020).

[6] M. Mahankali et al., in preparation.