Nonlinear optical responses of the Weyl-Kondo semimetal

High-harmonic generation via high-intensity pulse probes have been recently proposed to detect nontrivial topology through Berry curvature contributions to the second harmonic, in addition to probing many-body properties (such as charge dynamics) associated with strong correlations. However, it has been a challenge to determine how and which higher order harmonic spectral features correspond to band structure properties, calling for well-controlled models that can explore the signatures of strong correlation physics and topology. An elegant solution is the Weyl-Kondo semimetal model: the material Ce₃Bi₄Pd₃^1-3 and the concurrently developed theoretical model^4-5 display strong-correlation-driven topology. The Weyl-Kondo semimetal model can be tuned from trivial insulator to topological semimetal phases, and from the valence regime to the Kondo regime, independently. In this work, we study the high-harmonic generation of the Weyl-Kondo semimetal model, using a spin-orbit-coupled Peierls-substituted noncentrosymmetric periodic Anderson model. We study the response of the Weyl-Kondo semimetal phase and compare it to proximate trivial Kondo insulator and uncorrelated phases. We further uncover the significance of features of high-harmonic generation spectra to many-body dynamics through analyzing the nonequilibrium spectral function and band topology by detection of nontrivial Berry curvature-originated second harmonic response.

¹S. Dzsaber et al., PRL 118, 246601 2017

²S. Dzsaber et al., PNAS 118, 8 2021

³S. Dzsaber et al., Nat Commun 13, 5729 2022

⁴H.-H Lai, S. E. Grefe, S. Paschen, & Q. Si: PNAS 115, 93 2018

⁵S. E. Grefe, H.-H Lai, S. Paschen, & Q. Si: PRB 101, 075138 2020; arXiv:2012.15841; JPS Conf. Proc. 30, 011013 2020