At least four two- or quasi-one- dimensional allotropes and a mixture of them were theoretically predicted or experimentally observed for low-dimensional Te, namely the {\alpha}, \b{eta}, {\gamma}, {\delta} and chiral-{\alpha}+{\delta} phases. Among them the {\gamma} and {\alpha} phases were found the most stable phases for monolayer and thicker layers, respectively. Here, we found two novel low-dimensional phases, namely the {\epsilon} and {\zeta} phases. The {\zeta} phase is over 29 meV/Te more stable than and the {\epsilon} phase shows comparable stability with the most stable monolayer {\gamma} phase. The energetic difference between the {\zeta} and {\alpha} phases reduces with respect to the increased layer thickness and vanishes at the four-layer (12-sublayer) thickness, while this thickness increases under change doping. Both {\epsilon} and {\zeta} phases are metallic chains and layers, respectively. The {\zeta} phase, with very strong interlayer coupling, shows quantum well states in its layer-dependent bandstructures. These results provide significantly insight into the understanding of polytypism in Te few-layers and may boost tremendous studies on properties of various few-layer phases.

中文翻译：

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碲少层的两种超稳定新型同素异形体

对于低维 Te，至少有四个二维或准一维同素异形体和它们的混合物被理论预测或实验观察到，即 {\alpha}, \b{eta}, {\gamma}, {\delta } 和手性-{\alpha}+{\delta} 相。其中，{\gamma} 和 {\alpha} 相分别是单层和较厚层最稳定的相。在这里，我们发现了两个新的低维相，即 {\epsilon} 和 {\zeta} 相。{\zeta} 相比最稳定的单层 {\gamma} 相稳定超过 29 meV/Te，并且 {\epsilon} 相显示出相当的稳定性。{\zeta} 和 {\alpha} 相之间的能量差异随着层厚度的增加而减小，并在四层（12 个子层）厚度时消失，而该厚度在改变掺杂时增加。{\epsilon} 和 {\zeta} 相分别是金属链和层。{\zeta} 相具有非常强的层间耦合，在其依赖于层的能带结构中显示出量子阱态。这些结果为理解 Te 少层中的多型性提供了重要的见解，并可能促进对各种少层相性质的大量研究。