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arXiv 2107.05922cond-mat.supr-concond-mat.mtrl-sci
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压力下NiTe $_2$晶体结构、电子结构和输运性质的第一性原理研究

First-principles study of the crystal structure, electronic structure, and transport properties of NiTe$_2$ under pressure

Jian-Feng Zhang, Yawen Zhao, Kai Liu, Yi Liu, Zhong-Yi Lu

摘要:

最近的实验表明,在压力下对过渡金属二碲化物NiTe $_2$的不同观察:一个报告在12 GPa下的超导相变,而另一个观察到霍尔电阻率在16 GPa下的符号反转,而没有超导性的出现。为了澄清有争议的实验现象,我们进行了第一性原理电子结构计算压缩NiTe $_2$的结构搜索和优化。计算结果表明,当压力为$\sim$ 10 GPa时,NiTe $_2$可由层状P-3 m1相转变为立方Pa-3相.同时,P-3 m1和Pa-3相都具有非平凡的拓扑性质。根据电子-声子耦合理论计算的这两个相的超导$T_c$都接近于0 K。进一步的磁输运计算表明,与P-3 m1相的情况相反,Pa-3相的霍尔电阻的符号对压力和电荷掺杂敏感。我们对压缩NiTe $_2$的理论预测有待于仔细的实验检验。

英文摘要:

Recent experiments showed the distinct observations on the transition metal ditelluride NiTe$_2$ under pressure: one reported a superconducting phase transition at 12 GPa, whereas another observed a sign reversal of Hall resistivity at 16 GPa without the appearance of superconductivity. To clarify the controversial experimental phenomena, we have carried out first-principles electronic structure calculations on the compressed NiTe$_2$ with structure searching and optimization. Our calculations show that the pressure can transform NiTe$_2$ from a layered P-3m1 phase to a cubic Pa-3 phase at $\sim$10 GPa. Meanwhile, both the P-3m1 and Pa-3 phases possess nontrivial topological properties. The calculated superconducting $T_c$'s for these two phases based on the electron-phonon coupling theory both approach 0 K. Further magnetic transport calculations reveal that the sign of Hall resistance for the Pa-3 phase is sensitive to the pressure and the charge doping, in contrast to the case of the P-3m1 phase. Our theoretical predictions on the compressed NiTe$_2$ wait for careful experimental examinations.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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