We present the electronic characterization of single-layer 1H-TaSe₂ grown by molecular beam epitaxy using a combined angle-resolved photoemission spectroscopy, scanning tunneling microscopy/spectroscopy, and density functional theory calculations. We demonstrate that 3 × 3 charge-density-wave (CDW) order persists despite distinct changes in the low energy electronic structure highlighted by the reduction in the number of bands crossing the Fermi energy and the corresponding modification of Fermi surface topology. Enhanced spin–orbit coupling and lattice distortion in the single-layer play a crucial role in the formation of CDW order. Our findings provide a deeper understanding of the nature of CDW order in the two-dimensional limit.

中文翻译：

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单层TaSe _2中的持久性电荷密度波阶

我们介绍了电子束的分子束外延生长的单层1 H -TaSe ₂的电子表征，使用组合的角度分辨光发射光谱，扫描隧道显微镜/光谱和密度泛函理论计算。我们证明，尽管低能电子结构发生了明显变化，但3×3电荷密度波（CDW）顺序仍然存在，这一变化突出了穿过费米能量的能带数的减少以及费米表面拓扑的相应修改。单层中增强的自旋轨道耦合和晶格畸变在CDW阶的形成中起着至关重要的作用。我们的发现为二维极限中CDW顺序的性质提供了更深刻的理解。