Dynamical Kondo effect and Kondo destruction in effective models for quantum-critical heavy fermion metals

Kondo destruction that results in a sudden reconstruction of Fermi surface at the quantum critical point arises in certain heavy-fermion metals [1,2,3,4]. In the Kondo-destroyed phase, the STATIC Kondo singlet amplitude vanishes and, thus, a well-defined Kondo resonance is lost, but the Kondo singlet correlations remain at nonzero frequencies. We elucidate the dynamical Kondo effect in Bose-Fermi Kondo/Anderson models which unambiguously exhibit a Kondo-destruction QCP [5]. We demonstrate that the dynamical Kondo effect is important for the stability of Kondo-destruction quantum criticality and provides understanding of the enhanced effective mass in the Kondo-destroyed phase.

[1] Q. Si, S. Rabello, K. Ingersent and J. L. Smith, Nature 413, 804 (2001).
[2] S. Paschen et al., Nature 432, 881 (2004).
[3] H.Shishido et al, J. Phys. Soc. Jpn. 74, 1103 (2005).
[4] T. Park et al, Nature 440, 65 (2006).
[5] A. Cai, H. Hu, K. Ingersent, S. Paschen, and Q. Si, arXiv:1904.11471.