Journal Club

Title: Impact of the Fermi Arc Diversity on the Berry Curvature Dipole in Time Reversal Invariant Weyl Semimetals

Authors: Diego García Ovalle - Armando Pezo - Aurélien Manchon (Aix-Marseille Université, CNRS, CINaM, Marseille, France.)

Abstract:

Whereas anomalous Hall effect has been thought to only exist in materials presenting a net magnetization, such as ferro- or ferrimagnetic metals, recent progress has revealed that this is not the case. In particular, it has been recently proposed that in nonmagnetic crystals a transverse Hall current can develop at the second order in the electric field. This effect, tagged the nonlinear Hall effect, arises in certain non-centrosymmetric crystals and is driven by the Berry curvature dipole. Weyl Semimetals are particularly promising platforms for the observation of the nonlinear Hall effect because their bulk Fermi surface is composed of Weyl nodes with diverging Berry curvature. Nonetheless, Weyl Semimetals display another intriguing aspect that has remained scarcely addressed so far. Depending on the Weyl cone inclination, their surface feature a wide variety of trivial and non-trivial states, including Fermi pockets, arcs and track states.

In this work, adopting a model for noncentrosymmetric Weyl Semimetal, we investigate the impact of these surface states on the nonlinear Hall response. We show that depending on the slab geometry, surface states can have a dramatic impact on the nonlinear Hall effect, resulting in substantial thickness-dependence. We also extend our study to the realistic case of WTe2 thin film using a Wannier-projected tight-binding representation. Finally, we mention the intimate connection that is expected between the nonlinear Hall effect and the Orbital Edelstein Effect of these noncentrosymmetric materials.

Ref: arXiv:2206.08681