论文标题
层次1T'-TATE2中的夹层超结构的超快光学熔化2
Ultrafast optical melting of trimer superstructure in layered 1T'-TaTe2
论文作者
论文摘要
准二维过渡金属二色元是探索复杂相互作用引起的新兴纳米级现象的关键平台。在其自然时间尺度上访问基础自由度的访问激发了对自组织原子尺度敏感的高级超快探针的使用。在这里，我们报告了对TATE2的首次超快研究，该研究表现出独特的电荷和晶格三聚机顺序，其特征是从条纹状链条冷却到$（3 \ times 3）$的三聚体簇的上层结构。利用MEV规模的超快电子衍射，我们捕获了照片引起的TATE2结构动力学 - 暴露了快速$ \！1.4 $ PS的低温有序状态熔化，然后通过热量通过热量恢复到热群集上层结构中。密度功能的计算表明，与其他税收2化合物中电荷密度波的熔化不同，初始淬火是由trimer ta电荷转移触发的，这会破坏簇的稳定性。我们的作品为进一步探索和最终快速的磨砂器上层结构的光学和电子操作铺平了道路。
Quasi-two-dimensional transition-metal dichalcogenides are a key platform for exploring emergent nanoscale phenomena arising from complex interactions. Access to the underlying degrees-of-freedom on their natural time scales motivates the use of advanced ultrafast probes sensitive to self-organised atomic-scale patterns. Here, we report the first ultrafast investigation of TaTe2, which exhibits unique charge and lattice trimer order characterised by a transition upon cooling from stripe-like chains into a $(3 \times 3)$ superstructure of trimer clusters. Utilising MeV-scale ultrafast electron diffraction, we capture the photo-induced TaTe2 structural dynamics -- exposing a rapid $\approx\!1.4$ ps melting of its low-temperature ordered state followed by recovery via thermalisation into a hot cluster superstructure. Density-functional calculations indicate that the initial quench is triggered by intra-trimer Ta charge transfer which destabilises the clusters, unlike melting of charge density waves in other TaX2 compounds. Our work paves the way for further exploration and ultimately rapid optical and electronic manipulation of trimer superstructures.
