skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Concurrence of superconductivity and structure transition in Weyl semimetal TaP under pressure

Abstract

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 from I41md to P-6m2 at about 70 GPa. More importantly, ab-initial calculations reveal that the P-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.

Authors:
; ; ; ; ORCiD logo; ; ORCiD logo; ; ; ; ; ; ; ORCiD logo; ; ; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
Sponsoring Org.:
DOE - BASIC ENERGY SCIENCESNSFDOE-NNSAFOREIGN
OSTI Identifier:
1418051
Resource Type:
Journal Article
Resource Relation:
Journal Name: npj Quantum Materials; Journal Volume: 2; Journal Issue: 1
Country of Publication:
United States
Language:
ENGLISH
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY

Citation Formats

Li, Yufeng, Zhou, Yonghui, Guo, Zhaopeng, Han, Fei, Chen, Xuliang, Lu, Pengchao, Wang, Xuefei, An, Chao, Zhou, Ying, Xing, Jie, Du, Guan, Zhu, Xiyu, Yang, Huan, Sun, Jian, Yang, Zhaorong, Yang, Wenge, Mao, Ho-Kwang, Zhang, Yuheng, and Wen, Hai-Hu. Concurrence of superconductivity and structure transition in Weyl semimetal TaP under pressure. United States: N. p., 2017. Web. doi:10.1038/s41535-017-0066-z.
Li, Yufeng, Zhou, Yonghui, Guo, Zhaopeng, Han, Fei, Chen, Xuliang, Lu, Pengchao, Wang, Xuefei, An, Chao, Zhou, Ying, Xing, Jie, Du, Guan, Zhu, Xiyu, Yang, Huan, Sun, Jian, Yang, Zhaorong, Yang, Wenge, Mao, Ho-Kwang, Zhang, Yuheng, & Wen, Hai-Hu. Concurrence of superconductivity and structure transition in Weyl semimetal TaP under pressure. United States. doi:10.1038/s41535-017-0066-z.
Li, Yufeng, Zhou, Yonghui, Guo, Zhaopeng, Han, Fei, Chen, Xuliang, Lu, Pengchao, Wang, Xuefei, An, Chao, Zhou, Ying, Xing, Jie, Du, Guan, Zhu, Xiyu, Yang, Huan, Sun, Jian, Yang, Zhaorong, Yang, Wenge, Mao, Ho-Kwang, Zhang, Yuheng, and Wen, Hai-Hu. 2017. "Concurrence of superconductivity and structure transition in Weyl semimetal TaP under pressure". United States. doi:10.1038/s41535-017-0066-z.
@article{osti_1418051,
title = {Concurrence of superconductivity and structure transition in Weyl semimetal TaP under pressure},
author = {Li, Yufeng and Zhou, Yonghui and Guo, Zhaopeng and Han, Fei and Chen, Xuliang and Lu, Pengchao and Wang, Xuefei and An, Chao and Zhou, Ying and Xing, Jie and Du, Guan and Zhu, Xiyu and Yang, Huan and Sun, Jian and Yang, Zhaorong and Yang, Wenge and Mao, Ho-Kwang and Zhang, Yuheng and Wen, Hai-Hu},
abstractNote = {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 from I41md to P-6m2 at about 70 GPa. More importantly, ab-initial calculations reveal that the P-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.},
doi = {10.1038/s41535-017-0066-z},
journal = {npj Quantum Materials},
number = 1,
volume = 2,
place = {United States},
year = 2017,
month =
}
  • Cited by 8
  • By introducing a superconducting gap in Weyl or Dirac semimetals, the superconducting state inherits the nontrivial topology of their electronic structure. As a result, Weyl superconductors are expected to host exotic phenomena, such as nonzero-momentum pairing due to their chiral node structure, or zero-energy Majorana modes at the surface. These are of fundamental interest to improve our understanding of correlated topological systems, and, moreover, practical applications in phase-coherent devices and quantum applications have been proposed. Proximity-induced superconductivity promises to allow these experiments on nonsuperconducting Weyl semimetals. Here, we show a new route to reliably fabricate superconducting microstructures from the nonsuperconductingmore » Weyl semimetal NbAs under ion irradiation. Furthermore, the significant difference in the surface binding energy of Nb and As leads to a natural enrichment of Nb at the surface during ion milling, forming a superconducting surface layer (Tc ~ 3.5 K). Being formed from the target crystal itself, the ideal contact between the superconductor and the bulk may enable an effective gapping of the Weyl nodes in the bulk because of the proximity effect. Simple ion irradiation may thus serve as a powerful tool for the fabrication of topological quantum devices from monoarsenides, even on an industrial scale.« less
  • By introducing a superconducting gap in Weyl or Dirac semimetals, the superconducting state inherits the nontrivial topology of their electronic structure. As a result, Weyl superconductors are expected to host exotic phenomena, such as nonzero-momentum pairing due to their chiral node structure, or zero-energy Majorana modes at the surface. These are of fundamental interest to improve our understanding of correlated topological systems, and, moreover, practical applications in phase-coherent devices and quantum applications have been proposed. Proximity-induced superconductivity promises to allow these experiments on nonsuperconducting Weyl semimetals. Here, we show a new route to reliably fabricate superconducting microstructures from the nonsuperconductingmore » Weyl semimetal NbAs under ion irradiation. Furthermore, the significant difference in the surface binding energy of Nb and As leads to a natural enrichment of Nb at the surface during ion milling, forming a superconducting surface layer (Tc ~ 3.5 K). Being formed from the target crystal itself, the ideal contact between the superconductor and the bulk may enable an effective gapping of the Weyl nodes in the bulk because of the proximity effect. Simple ion irradiation may thus serve as a powerful tool for the fabrication of topological quantum devices from monoarsenides, even on an industrial scale.« less
  • Two-dimensional transition-metal dichalcogenide (TMDs) MoTe{sub 2} has attracted much attention due to its predicted Weyl semimetal state and a quantum spin Hall insulator in bulk and monolayer form, respectively. We find that the superconductivity in MoTe{sub 2} single crystal can be greatly enhanced by the partial substitution of the Te ions by the S ones. The maximum superconducting temperature T{sub C} of MoTe{sub 1.8}S{sub 0.2} single crystal is about 1.3 K. Compared with the parent MoTe{sub 2} single crystal (T{sub C} = 0.1 K), nearly 13-fold in T{sub C} is improved in the MoTe{sub 1.8}S{sub 0.2} one. The superconductivity has been investigated through themore » resistivity and magnetization measurements. MoTe{sub 2−x}S{sub x} single crystals belong to weak coupling superconductors and the improvement of the superconductivity may be related to the enhanced electron-phonon coupling induced by the S-ion substitution. A dome-shaped superconducting phase diagram is obtained in the S-doped MoTe{sub 2} single crystals. MoTe{sub 2−x}S{sub x} materials may provide a new platform for our understanding of superconductivity phenomena and topological physics in TMDs.« less