Nonlinear optical and electrical phenomena in topological semimetals
The Weyl semimetal is characterized by the monopole-like Weyl points that induce exotic surface Fermi arcs and the chiral anomaly effect. In this talk, I will introduce that Weyl points can also lead to a nonlinear anomalous Hall effect (AHE), i.e. a second-order response AHE coexisting with the time-reversal symmetry. We estimated that the novel Hall effect can be observable due to the large amplitude in realistic Weyl materials [1,2]. Further, Weyl semimetals also induce a colossal dc photocurrent under the light excitation, which is closely related to the Berry curvature in the band structure [3].
[1] Phys. Rev. B 97, 041101 (2018).
[2] arXiv:1804.11069
[3] arXiv:1803.00562