Charge density wave (CDW) is discovered within a wide interval in solids, however, its microscopic nature is still not transparent in most realistic materials, and the recently studied chiral ones with chiral structural distortion remain unclear. In this paper, we try to understand the driving forces of chiral CDW transition by chiral phonons from the electron-phonon coupling scenario. We use the prototypal monolayer 1T-TiSe₂ as a case study to unveil the absence of chirality in the CDW transition and propose a general approach, i.e., symmetry-breaking stimuli, to engineer the chirality of CDW in experiments. Inelastic scattering patterns are also studied as a benchmark of chiral CDW (CCDW, which breaks the mirror/inversion symmetry in 2D/3D systems). We notice that the anisotropy changing of Bragg peak profiles, which is contributed by the soft chiral phonons, can show a remarkable signature for CCDW. Our findings pave a path to understanding the CCDW from the chiral phonon perspective, especially in van der Waals materials, and provides a powerful way to manipulate the chirality of CDW.

电荷密度波 （CDW） 在固体中发现的间隔很宽，然而，在大多数现实材料中，它的微观性质仍然不透明，最近研究的具有手性结构畸变的手性波仍不清楚。在本文中，我们试图从电子-声子耦合情景中了解手性声子手性 CDW 跃迁的驱动力。我们使用原型单层 1T-TiSe₂ 作为案例研究来揭示 CDW 转变中手性的缺失，并提出了一种通用方法，即打破对称性刺激，以在实验中设计 CDW 的手性。非弹性散射图案也作为手性 CDW（CCDW，打破 2D/3D 系统中的镜像/反转对称性）的基准进行研究。我们注意到，由软手性声子贡献的布拉格峰剖面的各向异性变化可以显示出 CCDW 的显着特征。我们的发现为从手性声子角度理解 CCDW 铺平了道路，尤其是在范德华材料中，并提供了一种操纵 CDW 手性的有力方法。