Nonlinear Hall effect from long-lived valley-polarizing relaxons

Jae-Mo Lihm, Cheol-Hwan Park

Published 2024-03-08Version 1

The nonlinear Hall effect has attracted much attention due to the famous, widely adopted interpretation in terms of the Berry curvature dipole in momentum space. Using \textit{ab initio} Boltzmann transport equations, we find a 60\% enhancement in the nonlinear Hall effect of $n$-doped GeTe and its noticeable frequency dependence, qualitatively different from the predictions based on the Berry curvature dipole. The origin of these differences is long-lived valley polarization in the electron distribution arising from electron-phonon scattering. Our findings await immediate experimental confirmation.