论文标题
新颖的超结构二维材料1 $ \ textit {t} $ - vse $ _2 $在高压下
Novel Superstructure-Phase Two-Dimensional Material 1$\textit{T}$-VSe$_2$ at High Pressure
论文作者
论文摘要
上部结构可以通过打破其原始几何对称性来引起材料的多功能新特性。它是分层石墨烯样二维过渡金属元素（TMDS）的重要主题，但其起源尚不清楚。 Using diamond-anvil cell techniques, synchrotron x-ray diffraction, x-ray absorption, and the first-principles calculations, we show that the evolution from the weak Van der Waals bonding to the Heisenberg covalent bonding between layers induces an isostructural transition in quasi-two-dimensional 1$\textit{T}$-type VSe$_2$ at high pressure.此外，我们的结果表明，高压在15.5 GPA处诱导一个新型的上层建筑，而不是正常抑制它，这是出乎意料的。它是由费米表面嵌套驱动的，由压力诱导的失真增强。结果表明，上层建筑不仅出现在二维结构中，而且还可以在具有新的对称性并发展超导性的压力调节的三维结构中出现。
A superstructure can elicit versatile new properties of materials by breaking their original geometrical symmetries. It is an important topic in the layered graphene-like two-dimensional transition-metal dichalcogenides (TMDs), but its origin remains unclear. Using diamond-anvil cell techniques, synchrotron x-ray diffraction, x-ray absorption, and the first-principles calculations, we show that the evolution from the weak Van der Waals bonding to the Heisenberg covalent bonding between layers induces an isostructural transition in quasi-two-dimensional 1$\textit{T}$-type VSe$_2$ at high pressure. Furthermore, our results show that high-pressure induce a novel superstructure at 15.5 GPa, rather than suppress as it would normally, which is unexpected. It is driven by the Fermi surface nesting, enhanced by the pressure-induced distortion. The results suggest that the superstructure not only appears in the two-dimensional structure but also can emerge in the pressure-tuned three-dimensional structure with new symmetry and develop superconductivity.
