物理学进展

物理学进展 ›› 2022, Vol. 42 ›› Issue (6): 195-206.doi: 10.13725/j.cnki.pip.2022.06.001

• •    下一篇

RuX2 (X=P、As、Sb) 家族化合物中的压力诱导的超导和拓扑相变

  

  1. 1. 南京大学物理学院，固体微结构物理国家重点实验室，南京 210093; 2. 上海科技大学物质科学与技术学院，上海 201210; 3. 人工微结构科学与技术协同创新中心，南京大学，南京 210093
  • 出版日期:2022-12-20 发布日期:2023-03-22

Pressure-Induced Superconducting and Topological Phase Transitions in the RuX2 (X=P, As, Sb) Family Compounds

  1. 1. National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing 210093, China; 2. School of Physical Science and Technology, ShanghaiTech University, 393 Middle Huaxia Road, Shanghai 201210, China; 3. Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
  • Online:2022-12-20 Published:2023-03-22
  • Supported by:

    The financial support from the National Key R&D Program of China (grant nos. 2022YFA1403201), the National Natural Science Foundation of China (grant no. 12125404, 11974162, and 11834006), and the Fundamental Research Funds for the Central Universities. 

PDF (PC)

492

摘要：

作为热电材料 FeSb2 的姊妹材料，RuSb2 被广泛研究，但以前的工作主要集中在与 FeSb2 的比较上，尚未对 RuSb2 在压力下的性质进行深入研究。在本文中，我们研究了 RuSb2 在压力 下的性质，并探讨了其与 Ru 的磷族化合物 RuP2 和 RuAs2 之间晶体和电子结构的异同。我们 用晶体结构搜索方法结合第一性原理计算，发现该族化合物经历了一系列结构相变：（I）RuSb2： Pnnm → I4/mcm → I4/mmm；(II) RuP2：Pnnm → I41/amd → Cmcm；(III) RuAs2： Pnnm → P-62m。新发现的五个相在高压下都是热力学和动力学稳定的，并表现出金属性。RuSb2 和 RuP2 的四个高压相在泄压到零压后动力学依旧稳定。我们计算得到 RuSb2 的 I4/mcm 和 I4/mmm 相以及 RuP2 的 I41/amd 和 Cmcm 相的超导转变温度在 0 GPa 时分别约为 7.3 K、 10.9 K、13.0 K 和 10.1 K。另外，RuSb2 的 I4/mcm 和 I4/mmm 相以及 RuP2 的 I41/amd 相还具有拓扑非平庸的表面态。我们的研究表明，压力是调节 Ru 的磷族化合物结构、电子和超 导性质的有效方法。

关键词: 高压, 结构搜索, 相变, 超导电性, 拓扑材料

Abstract:

RuSb2, as a sister material of thermoelectric material FeSb2, has been extensively studied focusing on the comparisons with FeSb2, however, the properties of RuSb2 under pressure have not been surveyed thoroughly yet. In this work, we studied the properties of RuSb2 under pressure and explored the similarities and differences of crystal and electronic structures between the Ru-pnictides partners RuP2 and RuAs2. Using the crystal structures search method together with first-principles calculations, we found that this family undergoes a serial of structural phase transitions: (I) For RuSb2: Pnnm → I4/mcm → I4/mmm; (II) for RuP2: Pnnm → I41/amd → Cmcm; (III) for RuAs2: Pnnm → P-62m. The newly found five phases are all energetically and dynamically stable at high-pressure and exhibit metallic properties. The four high pressure phases of RuSb2 and RuP2 can be quenched to zero pressure. The superconducting transition temperatures of I4/mcm and I4/mmm phases of RuSb2 and I41/amd and Cmcm phase of RuP2 are predicted to be approximately 7.3 K, 10.9 K, 13.0 K, and 10.1 K at 0 GPa, respectively. In addition, the I4/mcm and I4/mmm phases of RuSb2 and the I41/amd phase of RuP2 exhibit non-trivial topological properties. Our studies illustrate that pressure is an effective way to tune the structural, electronic, and superconducting behavior of the Ru-pnictides compounds.

Key words: high-pressure, crystal structures search method, phase transition, superconductor, topological materials

中图分类号: