Pressure-induced superconductivity in MoP

• Published in: npj quantum materials 2018-05, Vol.3 (1), Article 28
• Main Authors: Chi, Zhenhua, Chen, Xuliang, An, Chao, Yang, Liuxiang, Zhao, Jinggeng, Feng, Zili, Zhou, Yonghui, Zhou, Ying, Gu, Chuanchuan, Zhang, Bowen, Yuan, Yifang, Kenney-Benson, Curtis, Yang, Wenge, Wu, Gang, Wan, Xiangang, Shi, Youguo, Yang, Xiaoping, Yang, Zhaorong
• Format: Article
• Language: English
• Subjects: 639/766/119/1003; 639/766/119/2792/4128; Condensed Matter Physics; Crystal structure; Crystals; Density functional theory; Fermions; Molybdenum; Phase transitions; Phosphides; Physics; Physics and Astronomy; Pressure; Quantum phenomena; Quantum Physics; Structural Materials; Superconductivity; Surfaces and Interfaces; Synchrotron radiation; Thin Films; Topological superconductors; Topology; Transition temperature; Transport; Tungsten carbide; Tungsten compounds
• ISSN: 2397-4648; 2397-4648
• DOI: 10.1038/s41535-018-0102-7

Topological semimetal, a novel state of quantum matter hosting exotic emergent quantum phenomena dictated by the nontrivial band topology, has emerged as a new frontier in condensed-matter physics. Very recently, the coexistence of triply degenerate points of band crossing and Weyl points near the Fermi level was theoretically predicted and experimentally identified in MoP. Via high-pressure electrical transport measurements, we report here the emergence of pressure-induced superconductivity in MoP with a critical transition temperature T c of ca. 2.5 K at ca. 30 GPa. No structural phase transition is observed up to ca. 60 GPa via synchrotron X-ray diffraction study. Accordingly, the topologically nontrivial band protected by the crystal structure symmetries and superconductivity are expected to coexist at pressures above 30 GPa, consistent with density functional theory calculations. Thus, the pressurized MoP represents a promising candidate of topological superconductor. Our finding is expected to stimulate further exploitation of exotic emergent quantum phenomena in novel unconventional fermion system. Superconductivity: under pressure Molybdenum phosphide becomes superconducting above 30 GPa, with a critical transition temperature of 2.5 K. A team led by Youguo Shi, Xiaoping Yang and Zhaorong Yang from the Chinese Academy of Sciences perform high-pressure electrical transport measurements in molybdenum phosphide, which is a recently proved topological material hosting exotic fermions. They apply pressure over 90 GPa and observe a superconducting transition above 30 GPa with a critical transition temperature of 2.5 K, which increases to 4 K at 95 GPa. Meanwhile, the compound crystalizes into a (tungsten carbide) WC-type structure where the topological properties are predicted from ambient pressure up to 60 GPa. They expect that topological fermions and superconductivity could coexist under a pressure between 30 GPa and 60 GPa, suggesting a possible candidate for topological superconductivity.