Effects of strong correlations on the nonlinear response in Weyl-Kondo semimetals

TL;DR

This paper investigates how strong electron correlations influence the nonlinear electrical responses in Weyl-Kondo semimetals, explaining the giant nonlinear Hall effect observed in experiments through theoretical modeling.

Contribution

It provides the first theoretical analysis connecting strong correlation effects with nonlinear responses in Weyl-Kondo semimetals using dynamical mean-field theory.

Findings

Strong correlations enhance nonlinear conductivities.

The giant nonlinear Hall effect can be explained by correlation effects.

Temperature dependence of nonlinear responses is clarified.

Abstract

Nonlinear responses give rise to various exciting phenomena, which are forbidden in linear responses. Among them, one of the most fascinating phenomena is the recently observed giant spontaneous Hall effect in $\mathrm{Ce_{3}Bi_{4}Pd_{3}}$. This material is a promising candidate for a Weyl-Kondo semimetal, and this experiment implies that strong correlation effects can enhance the nonlinear Hall effect. However, most theoretical studies on nonlinear responses have been limited to free systems, and the connection between nonlinear responses and strong correlation effects is poorly understood. Motivated by these experiments and recent theoretical advances to analyze strong correlation effects on the nonlinear response, we study a periodic Anderson model describing $\mathrm{Ce_{3}Bi_{4}Pd_{3}}$ using the dynamical mean-field theory. We calculate the nonlinear longitudinal conductivity and the nonlinear Hall conductivity using the Kubo formula extended to the nonlinear response regime and clarify their temperature dependences. We numerically show that strong correlations can enhance nonlinear conductivities, and we conclude that the magnitude of the experimentally observed giant nonlinear Hall effect can be explained by strong correlation effects.