Giant Magnetochiral Anisotropy in Weyl Semimetal WTe2 Induced by Diverging Berry Curvature

The concept of Berry curvature is essential for various transport phenomena. However, an effect of the Berry curvature on magnetochiral anisotropy, i.e., nonreciprocal magnetotransport, is still elusive. Here, we report that the Berry curvature induces the large magnetochiral anisotropy. In Weyl semimetal WTe2 , we observe the strong enhancement of the magnetochiral anisotropy when the Fermi level is located near the Weyl points. Notably, the maximal figure of merit gamma over bar reaches 1.2 x 10-6 m2 T-1 A-1 , which is the largest ever reported in bulk materials. Our semiclassical calculation shows that the diverging Berry curvature at the Weyl points strongly enhances the magnetochiral anisotropy.

Automated summary

The concept of Berry curvature is crucial for a variety of transport phenomena, but its effect on magnetochiral anisotropy, i.e., nonreciprocal magnetotransport, remains unclear. We demonstrate in Weyl semimetal WTe2 that the Berry curvature induces significant enhancement of magnetochiral anisotropy. Notably, the maximal figure of merit γ reaches 1.2 x 10-6 m2 T-1 A-1, which is the highest value reported in bulk materials to date. Our semiclassical calculation reveals that the diverging Berry curvature at the Weyl points strongly amplifies the magnetochiral anisotropy.