|
1
|
Zhou F, Ding G, Cheng Z, Surucu G, Chen H, Wang X. Pnma metal hydride system LiBH: a superior topological semimetal with the coexistence of twofold and quadruple degenerate topological nodal lines. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:365502. [PMID: 32357343 DOI: 10.1088/1361-648x/ab8f5d] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 05/01/2020] [Indexed: 06/11/2023]
Abstract
To date, a handful of topological semimetals (TMs) with multiple types of topological nodal line (TNL) states have been theoretically predicted in novel materials. However, their TNLs are often affected by many factors, such as spin-orbit coupling (SOC) effect, strain, and the extraneous bands near the band crossing points, and therefore, the TNL states cannot be easily verified by experiments. Here, by using first-principles calculations, we report that the Pnma LiBH is a potential TM with twofold and quadruple degenerate topological nodal lines. These TNLs situate very close to the Fermi level, and do not coexist with other extraneous bands. More importantly, the TNLs of this material are very robust to the effect of SOC, uniform strain, and biaxial strain. The nontrivial band structure in LiBH produces drum-head-like surface states in the (001) surface projection. Our result reveals that LiBH material is an excellent candidate to study the multiple kinds of TNLs.
Collapse
Affiliation(s)
- Feng Zhou
- School of Physical Science and Technology, Southwest University, Chongqing 400715, People's Republic of China
| | - Guangqian Ding
- School of Science, Chongqing University of Posts and Telecommunications, Chongqing 400065, People's Republic of China
| | - Zhenxiang Cheng
- Institute for Superconducting and Electronic Materials (ISEM), University of Wollongong, Wollongong 2500, Australia
| | - Gokhan Surucu
- Department of Physics, Middle East Technical University, Turkey
- Department of Electric and Energy, Ahi Evran University, Turkey
| | - Hong Chen
- School of Physical Science and Technology, Southwest University, Chongqing 400715, People's Republic of China
| | - Xiaotian Wang
- School of Physical Science and Technology, Southwest University, Chongqing 400715, People's Republic of China
| |
Collapse
|
|
2
|
Wang H, He Y, Liu Y, Yuan Z, Jia S, Ma L, Liu XJ, Wang J. Ferromagnetic tip induced unconventional superconductivity in Weyl semimetal. Sci Bull (Beijing) 2020; 65:21-26. [PMID: 36659064 DOI: 10.1016/j.scib.2019.11.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 10/21/2019] [Accepted: 10/31/2019] [Indexed: 01/21/2023]
Abstract
The metallic tip-induced superconductivity in normal Weyl semimetal offers a promising platform to study topological superconductivity, which is currently a research focus in condensed matter physics. Here we experimentally uncover that unconventional superconductivity can be induced by hard point contact (PC) method of ferromagnetic tips in TaAs single crystals. The magneto-transport measurements of the ferromagnetic tip-induced superconducting (FTISC) states exhibit the quantum oscillations, which reveal that the superconductivity is induced in the topologically nontrivial Fermi surface of the Weyl semimetal, and show compatibility of ferromagnetism and induced superconductivity. We further measure the point contact spectra (PCS) of tunneling transport for FTISC states which are potentially of nontrivial topology. Considering that the magnetic Weyl semimetal with novel superconductivity is hard to realize in experiment, our results show a new route to investigate the unconventional superconductivity by combining the topological semimetal with ferromagnetism through hard PC method.
Collapse
Affiliation(s)
- He Wang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China; Tianjin International Center for Nano Particles and Nano Systems, Tianjin University, Tianjin 300072, China; Department of Physics, Capital Normal University, Beijing 100048, China
| | - Yingping He
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China; Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Yiyuan Liu
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China; Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Zhujun Yuan
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China; Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Shuang Jia
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China; Collaborative Innovation Center of Quantum Matter, Beijing 100871, China; CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Lei Ma
- Tianjin International Center for Nano Particles and Nano Systems, Tianjin University, Tianjin 300072, China.
| | - Xiong-Jun Liu
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China; Collaborative Innovation Center of Quantum Matter, Beijing 100871, China; CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China; Beijing Academy of Quantum Information Sciences, Beijing 100193, China.
| | - Jian Wang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China; Collaborative Innovation Center of Quantum Matter, Beijing 100871, China; CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China; Beijing Academy of Quantum Information Sciences, Beijing 100193, China.
| |
Collapse
|