A non-linear Hall effect at zero field in a chiral nonmagnetic compound

The Hall effect arising from the Berry curvature is one of the most important topological phenomena. In the linear response regime, such a Hall effect appears only in the time-reversal symmetry breaking condition; this is well-known as an anomalous Hall effect. By contrast, the recent studies have proposed that in the nonlinear response regime, a Hall voltage can be observed due to the Berry curvature even in time-reversal invariant systems. These works demonstrate that the new-type of Hall effect is a powerful probe for investigating Berry physics in the nonmagnetic topological materials. However, experimental studies on this nonlinear Hall effect are still lacking.
Here, we report the observation of nonlinear Hall effect in a chiral nonmagnetic compound. We find that an electric current induces a nonlinear Hall voltage under time-reversal invariant conditions. The sign of the voltage at 4.2 K depends strongly on the direction of the chirality of crystal structure, which is consistent with the theoretical calculations. Furthermore, this nonlinear Hall effect becomes smaller at higher temperatures but is still observable even at room temperature.