Anisotropic Response of Type-II Weyl Semimetal TaIrTe₄ under Ultrafast Photoexcitation

We perform angle-resolved transient reflection spectroscopy to study the dynamical evolution of anisotropic properties of Type-II Weyl semimetal TaIrTe₄ under photo excitation. The dynamical relaxation of photoexcited carriers exhibits three exponential decay components relating to optical/acoustic phonon cooling and subsequent heat transfer to the substrate. The angle resolved measurement reveals that the anisotropy of reflectivity is reduced in the pump induced quasi-equilibrium state, suggesting a reduction of the anisotropy in dynamical conductivity in hot carrier dominated regime. These results are indispensable in designing high field, angle sensitive electronic, optoelectronic and remote sensing devices exploiting the dynamical electronic anisotropy with TaIrTe₄.