Chiral-Anomaly-Induced Nonlinear Hall Effect in Tilted Weyl Semimetals

Weyl semimetals (WSMs) are a new class of quantum materials that can host massless quasiparticles called Weyl fermions. One unique feature of WSMs is the chiral anomaly – a pair of Weyl nodes of opposite chiralities acts as source and drain of electrons in the presence of parallel electric and magnetic fields. Hence, a steady-state density difference between a pair of Weyl nodes is established when the chiral pumping and the internode relaxation reach a balance, which conspires with the anomalous velocity of the electrons to give rise to a nonlinear Hall effect. In this work, we find that the chiral-anomaly-induced nonlinear Hall (CNH) effect requires inversion symmetry breaking as well as asymmetric Fermi surfaces, which may be realized in tilted WSMs wherein the overall tilting of the Weyl cones is asymmetric about the Γ point. We also show that this effect is different from the Berry-curvature-induced nonlinear Hall effect that exist in time-reversal invariant materials. We will also discuss the CNH effect in recently discovered magnetic noncentrosymmetric WSMs.