Layered type-II Weyl semimetals, such as WTe₂, MoTe₂, and TaIrTe₄ have been demonstrated as a supreme photodetection material with topologically enhanced responsivity and specific sensitivity to the orbital angular momentum of light. Toward future device applications with high performance and ultrafast response, it is necessary to understand the dynamical processes of hot carriers and transient electronic properties of these materials under photoexcitation. In this work, mid-infrared ultrafast spectroscopy is performed to study the dynamical evolution of the anisotropic response of TaIrTe₄. 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 ultrafast transient dynamics imply that TaIrTe₄ is an ideal material candidate for ultrafast optoelectronic applications, especially in the long-wavelength region. The angle-resolved measurement of transient reflection reveals that the reflectivity becomes less anisotropic in the quasi-equilibrium state, indicating a reduction in the anisotropy of dynamical conductivity in presence of photoexcited hot carriers. The results are indispensable in material engineering for polarization-sensitive optoelectronics and high field electronics.

层状II型Weyl半金属（例如WTe ₂，MoTe ₂和TaIrTe _4）已被证明是一种顶级的光电检测材料，具有拓扑增强的响应能力和对光的轨道角动量的比敏感度。对于高性能和超快速响应的未来设备应用，有必要了解热激发的动态过程以及这些材料在光激发下的瞬态电子特性。在这项工作中，进行了中红外超快光谱研究TaIrTe ₄各向异性响应的动力学演化。。光激发载流子的动态弛豫表现出三个指数衰减分量，这些衰减分量与光/声子声子冷却以及随后向基底的热传递有关。超快的瞬态动力学特性表明TaTerTe ₄是超快光电应用的理想材料，特别是在长波长区域。瞬态反射的角度分辨测量表明，在准平衡状态下反射率的各向异性变小，这表明在存在光激发热载流子的情况下，动态电导率的各向异性减小了。在偏振敏感的光电和高场电子学的材料工程中，结果是必不可少的。