Kondo Effect in Nonlinear Response

Chiral spin correlations and magnetic orders lead to a variety of interesting transport properties, such as the topological Hall effect. They give rise to a large anomalous Hall effect in antiferromagnets and facilitate the detection of exotic magnetic excitations like skyrmions. Further studies have identified additional chiral effects, such as the chiral Hall effect and nonreciprocal responses. Recent experiments have also suggested potential signatures of quantum fluctuations affecting the AHE and nonlinear responses. However, most theoretical studies to date have treated spins as classical, and thus the role of quantum fluctuations in chirality-related transport phenomena has remained largely unexplored.

In this work, we reveal that the coexistence of quantum fluctuations and chiral spin correlations enhances the nonreciprocal current at low temperatures, which increases logarithmically with respect to the temperature. Using the Green’s function method and a scattering theory approach, we show that the enhancement occurs through a scattering process similar to that of the Kondo effect. The quantum enhancement reaches the same order as the classical one near the Kondo temperature, indicating the importance of quantum fluctuation. On the other hand, no such correction exists in the anomalous Hall effect. The results provide a foundational understanding of the effect of quantum fluctuation and demonstrate its importance in predicting material properties.