College of Chemistry and Molecular Engineering, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing, 100871, P. R. China.
Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, P. R. China.
Nat Commun. 2023 Apr 19;14(1):2223. doi: 10.1038/s41467-023-37927-6.
The chiral charge density wave is a many-body collective phenomenon in condensed matter that may play a role in unconventional superconductivity and topological physics. Two-dimensional chiral charge density waves provide the building blocks for the fabrication of various stacking structures and chiral homostructures, in which physical properties such as chiral currents and the anomalous Hall effect may emerge. Here, we demonstrate the phase manipulation of two-dimensional chiral charge density waves and the design of in-plane chiral homostructures in 1T-TaS. We use chiral Raman spectroscopy to directly monitor the chirality switching of the charge density wave-revealing a temperature-mediated reversible chirality switching. We find that interlayer stacking favours homochirality configurations, which is confirmed by first-principles calculations. By exploiting the interlayer chirality-locking effect, we realise in-plane chiral homostructures in 1T-TaS. Our results provide a versatile way to manipulate chiral collective phases by interlayer coupling in layered van der Waals semiconductors.
手性电荷密度波是凝聚态物质中的一种多体集体现象，可能在非常规超导和拓扑物理中发挥作用。二维手性电荷密度波为各种堆叠结构和手性同型结构的制造提供了构建块，其中可能出现手性电流和反常霍尔效应等物理性质。在这里，我们展示了二维手性电荷密度波的相操控和 1T-TaS 中的面内手性同型结构设计。我们使用手性拉曼光谱直接监测电荷密度波的手性切换，揭示了温度介导的可逆手性切换。我们发现层间堆积有利于同手性构型，这得到了第一性原理计算的证实。通过利用层间手性锁定效应，我们在 1T-TaS 中实现了面内手性同型结构。我们的结果提供了一种通过层状范德华半导体中的层间耦合来操纵手性集体相的通用方法。
