High-order harmonic generation in type-II Weyl semimetal TaIrTe ₄

In condensed matter physics, the study of topological materials has recently extended to the topological chirality of Weyl nodes in type-II Weyl semimetals such as TaIrTe₄. High-order harmonic generation under strong-field excitation serves as an all-optical probe of their unique electronic topology. Here, we report the high-order harmonic generation in TaIrTe₄, which exhibits a strong handedness-dependent asymmetry in the ellipticity dependence of harmonic yield, as well as the continuously tunable polarization states of harmonics driven by an elliptically polarized laser. By analyzing the underlying mechanisms, we identify the imprint of the distinct properties of TaIrTe₄ within the harmonic emissions, including the broken inversion symmetry, the tilted chiral Weyl cone and Berry curvature. Our results establish the potential possibility of high-order harmonic generation as a sensitive probe for complex topological properties in quantum materials under strong-field conditions.