Investigation of nonlinear Hall effect in a topological semimetal

Topological semimetals exhibit novel quantum phases and properties of matter, such as surface/edge states, topological Fermi arc, highly anisotropic negative longitudinal magnetoresistance, and exotic Hall transports. Recently, a new type of Hall effect is discovered in time-reversal symmetric topological semimetals in which the Hall conductivity is proportional to the square of the applied voltage. This unusual Hall signal is resulting from Berry curvature dipole (BCD) allowed from broken crystalline symmetry. In this talk, we will present electronic and transport properties of a topological semimetal exhibiting BCD-induced nonlinear Hall effect using angle-resolved photoemission spectroscopy, first-principles calculations, and transport measurements. We find that substantial nonlinear Hall conductivity, mainly contributed from the BCD around Weyl points located near the Fermi energy.