论文标题
交替在散装6R-TAS2中交替进行超导和电荷密度波单层
Alternating superconducting and charge density wave monolayers within bulk 6R-TaS2
论文作者
论文摘要
Van der Waals（VDW）异质结构继续引起强烈的兴趣，作为设计具有新型特性的材料的途径，这些材料在自然存在的材料中找不到。不幸的是，目前，这种方法仅限于几层可以彼此堆叠的层。在这里，我们报告了一种散装材料，该材料包括超导单层与显示电荷密度波（CDW）的单层中间的层次。这种大量VDW异质结构是通过在惰性气氛中在800°C下1T-TAS2到6R的相变创建的。电子显微镜分析直接显示了所得大量6R相内的交替1T和1H单层的存在。它的超导转变（TC）在2.6 K处发现，超过TAS2的大量2H相的TC。通过去角质6R-TAS2，然后重新添加其层，可以将超导温度进一步提高至3.6 K。我们认为，在6R-TAS2内的超导和CDW的共存源于相邻1H和1T单层的性质的合并，前者在该特性中占主导地位的超导状态，而后者则是CDW行为。
Van der Waals (vdW) heterostructures continue to attract intense interest as a route of designing materials with novel properties that cannot be found in naturally occurring materials. Unfortunately, this approach is currently limited to only a few layers that can be stacked on top of each other. Here we report a bulk material consisting of superconducting monolayers interlayered with monolayers displaying charge density waves (CDW). This bulk vdW heterostructure is created by phase transition of 1T-TaS2 to 6R at 800 °C in an inert atmosphere. Electron microscopy analysis directly shows the presence of alternating 1T and 1H monolayers within the resulting bulk 6R phase. Its superconducting transition (Tc) is found at 2.6 K, exceeding the Tc of the bulk 2H phase of TaS2. The superconducting temperature can be further increased to 3.6 K by exfoliating 6R-TaS2 and then restacking its layers. Using first-principles calculations, we argue that the coexistence of superconductivity and CDW within 6R-TaS2 stems from amalgamation of the properties of adjacent 1H and 1T monolayers, where the former dominates the superconducting state and the latter the CDW behavior.
