Nonlinear Hall effect in bilayer WTe2 induced by strong laser field

Abstract

The geometric nature of Bloch electrons has recently come into focus of studies in nonlinear optics. In this regard, the Weyl semimetals, with their significant Berry curvature at Weyl nodes, are of particular interest. The recently discovered nonlinear Hall phenomena in Weyl semimetals (mainly 2nd order responses), provide a unique avenue to explore the topological properties of emergent quantum materials [1]. While previous studies in nonlinear optics have explored various mechanisms in Weyl semimetals, such as Bloch oscillations, intraband motions, and high harmonic generation, the relationship between nonlinear Hall phenomena and nonlinear optics remains unexamined. Our study presents the first investigation of the relationship between nonlinear Hall effects and nonlinear optical responses in Weyl Dirac nodes, ranging from perturbative to nonperturbative regimes. Focusing on the mid-infrared frequency range, we probe the effects of intensity and frequency dependence, including energy cutoffs and the interplay between interband and intraband processes, using time-dependent first-principles formalismjournal articl