论文标题
在二维NBSE $ _ {2} $中揭示由PEIERLS不稳定引起的电荷密度波
Revealing the Charge Density Wave caused by Peierls instability in two-dimensional NbSe$_{2}$
论文作者
论文摘要
由PEIERLS不稳定引起的二维（2D）材料中电荷密度波（CDW）的形成是一个有争议的话题。这项研究调查了费米表面嵌套在2H-NBSE $ _ {2} $材料中引起CDW状态的广泛争议作用。根据扫描隧道显微镜图像和第一原理模拟的特征，确定了四个NBSE $ _ {2} $结构（即正常，条纹，填充和空心结构）。计算表明，填充阶段对应于Peierls的描述。也就是说，它在CDW Brillouin区域边界上表现出完全打开的间隙，从而导致状态密度和扫描隧道光谱光谱的费米水平下降。正常相中的电子敏感性和声子不稳定性表明，费米表面嵌套是由两个嵌套向量触发的，而仅参与一个嵌套矢量会导致条纹相。这项全面的研究表明，NBSE $ _ {2} $的填充阶段可以归类为2D系统中的PEIERLS-INSCON诱导的CDW。
The formation of a charge density wave (CDW) in two-dimensional (2D) materials caused by Peierls instability is a controversial topic. This study investigates the extensively debated role of Fermi surface nesting in causing the CDW state in 2H-NbSe$_{2}$ materials. Four NbSe$_{2}$ structures (i.e., normal, stripe, filled, and hollow structures) are identified on the basis of the characteristics in scanning tunneling microscopy images and first-principles simulations. The calculations reveal that the filled phase corresponds to Peierls' description; that is, it exhibits fully opened gaps at the CDW Brillouin zone boundary, resulting in a drop at the Fermi level in the density of states and the scanning tunneling spectroscopy spectra. The electronic susceptibility and phonon instability in the normal phase indicate that the Fermi surface nesting is triggered by two nesting vectors, whereas the involvement of only one nesting vector leads to the stripe phase. This comprehensive study demonstrates that the filled phase of NbSe$_{2}$ can be categorized as a Peierls-instability-induced CDW in 2D systems.
