论文标题
半金属t $ _ {d} $ - wte $ _ {2} $在锂插入中诱导的阶段
A Gapped Phase in Semimetallic T$_{d}$-WTe$_{2}$ Induced by Lithium Intercalation
论文作者
论文摘要
Weyl Semimetal wte $ _ {2} $显示了几种相关的电子行为，例如量子自旋大厅效应，超导性，铁电性和可能的激子绝缘子状态，所有这些都可以通过各种物理和化学方法来调节。在这里，我们发现了由锂插入引起的WTE $ _ {2} $中的新电子阶段。新阶段的电阻率随温度降低而增加，其载体密度几乎比半金属t $ _ {d} $相位的载体密度低两个数量级，该载体密度是由原位霍尔测量值探测为lithium Inturecalation的函数的。我们的理论计算预测，新的熔融相是一个电荷密度波（CDW）相，带隙为〜0.14 eV，与原位传输数据非常吻合。新阶段在结构上与初始t $ _ {d} $相位，其特征在于极化角度依赖性拉曼光谱，并且在新阶段预测了接近6％的大晶格失真。因此，我们报告了T $ _ {D} $ -WTE $ _ {2} $中CDW的第一个实验证据，将wte $ _ {2} $投影为研究CDW和超导性之间的相互作用的新游乐场。我们发现在二维（2D）半金属中新的差异相的发现也证明了电化学插入，作为一种强大的调谐旋钮，用于调节2D材料中的电子密度和相位稳定性。
The Weyl semimetal WTe$_{2}$ has shown several correlated electronic behaviors, such as the quantum spin Hall effect, superconductivity, ferroelectricity, and a possible exciton insulator state, all of which can be tuned by various physical and chemical approaches. Here, we discover a new electronic phase in WTe$_{2}$ induced by lithium intercalation. The new phase exhibits an increasing resistivity with decreasing temperature and its carrier density is almost two orders of magnitude lower than the carrier density of the semi-metallic T$_{d}$ phase, probed by in situ Hall measurements as a function of lithium intercalation. Our theoretical calculations predict the new lithiated phase to be a charge density wave (CDW) phase with a bandgap of ~ 0.14 eV, in good agreement with the in situ transport data. The new phase is structurally distinct from the initial T$_{d}$ phase, characterized by polarization angle-dependent Raman spectroscopy, and large lattice distortions close to 6 % are predicted in the new phase. Thus, we report the first experimental evidence of CDW in T$_{d}$-WTe$_{2}$, projecting WTe$_{2}$ as a new playground for studying the interplay between CDW and superconductivity. Our finding of a new gapped phase in a two-dimensional (2D) semi-metal also demonstrates electrochemical intercalation as a powerful tuning knob for modulating electron density and phase stability in 2D materials.
