Concurrence of superconductivity and structure transition in Weyl semimetal TaP under pressure
Concurrence of superconductivity and structure transition in Weyl semimetal TaP under pressure
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外尔半金属TaP在压力下同时发生超导和结构转变
DOI：
10.1038/s41535-017-0066-z
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发表时间：
2017-12-01
影响因子：
5.7
通讯作者：
Wen, Hai-Hu
中科院分区：
文献类型：
--
作者：
Li, Yufeng;Zhou, Yonghui;Wen, Hai-Hu
韦尔半金属定义了一种具有三维狄拉克锥的材料，由于空间反转或时间反转对称性的破坏，狄拉克锥成对出现。超导是成对电子的量子凝聚状态。将外尔半金属转变为超导态对于获得一些前所未有的发现非常重要。在这项工作中，通过在高达约 100 GPa 的压力下对最近认可的 Weyl 半金属 TaP 进行电阻测量，我们展示了在约 70 GPa 的压力下超导性和结构转变的同时发生。研究发现，当压力降低时，超导性变得更加明显，而当压力完全释放时，超导性保持不变。高压 X 射线衍射测量也证实了在约 70 GPa 下从 I41md 到 P-6m2 的结构相变。更重要的是，ab-initial计算表明P-6m2相是一种新的Weyl半金属相，并且在相同能级上只有一组Weyl点。我们通过高压在 TaP 中发现超导性将促进对外尔半金属中超导性和马约拉纳费米子的研究。
Weyl semimetal defines a material with three-dimensional Dirac cones, which appear in pair due to the breaking of spatial inversion or time reversal symmetry. Superconductivity is the state of quantum condensation of paired electrons. Turning a Weyl semimetal into superconducting state is very important in having some unprecedented discoveries. In this work, by doing resistive measurements on a recently recognized Weyl semimetal TaP under pressures up to about 100 GPa, we show the concurrence of superconductivity and a structure transition at about 70 GPa. It is found that the superconductivity becomes more pronounced when decreasing pressure and retains when the pressure is completely released. High-pressure x-ray diffraction measurements also confirm the structure phase transition fromI41mdtoP-6m2 at about 70 GPa. More importantly, ab-initial calculations reveal that theP-6m2 phase is a new Weyl semimetal phase and has only one set of Weyl points at the same energy level. Our discovery of superconductivity in TaP by high pressure will stimulate investigations on superconductivity and Majorana fermions in Weyl semimetals.