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Your search keyword '"Nie, Si-Min"' showing total 7 results
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7 results on '"Nie, Si-Min"'

1. Time-reversal symmetry breaking driven topological phase transition in EuB$_6$

Author

Gao, Shun-Ye, Xu, Sheng, Li, Hang, Yi, Chang-Jiang, Nie, Si-Min, Rao, Zhi- Cheng, Wang, Huan, Hu, Quan-Xin, Chen, Xue-Zhi, Fan, Wen-Hui, Huang, Jie- Rui, Huang, Yao-Bo, Pryds, Nini, Shi, Ming, Wang, Zhi-Jun, Shi, You-Guo, Xia, Tian-Long, Qian, Tian, and Ding, Hong

Subjects
Condensed Matter - Materials Science, Condensed Matter - Strongly Correlated Electrons
Abstract

The interplay between time-reversal symmetry (TRS) and band topology plays a crucial role in topological states of quantum matter. In time-reversal-invariant (TRI) systems, the inversion of spin-degenerate bands with opposite parity leads to nontrivial topological states, such as topological insulators and Dirac semimetals. When the TRS is broken, the exchange field induces spin splitting of the bands. The inversion of a pair of spin-splitting subbands can generate more exotic topological states, such as quantum anomalous Hall insulators and magnetic Weyl semimetals. So far, such topological phase transitions driven by the TRS breaking have not been visualized. In this work, using angle-resolved photoemission spectroscopy, we have demonstrated that the TRS breaking induces a band inversion of a pair of spin-splitting subbands at the TRI points of Brillouin zone in EuB$_6$, when a long-range ferromagnetic order is developed. The dramatic changes in the electronic structure result in a topological phase transition from a TRI ordinary insulator state to a TRS-broken topological semimetal (TSM) state. Remarkably, the magnetic TSM state has an ideal electronic structure, in which the band crossings are located at the Fermi level without any interference from other bands. Our findings not only reveal the topological phase transition driven by the TRS breaking, but also provide an excellent platform to explore novel physical behavior in the magnetic topological states of quantum matter., Comment: 22 pages, 7 figures, accepted by Phys. Rev. X

Published
2021
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2. First principle calculation of the effective Zeeman's couplings in topological materials

Author

Song, Zhi-Da, Sun, Song, Xu, Yuan-Feng, Nie, Si-Min, Weng, Hong-Ming, Fang, Zhong, and Dai, Xi

Subjects
Condensed Matter - Materials Science
Abstract

In this paper, we propose a first principle calculation method for the effective Zeeman's coupling based on the second perturbation theory and apply it to a few topological materials. For Bi and Bi$_2$Se$_3$, our numerical results are in good accord with the experimental data; for Na$_3$Bi, TaN, and ZrTe$_5$, the structure of the multi-bands Zeeman's couplings are discussed. Especially, we discuss the impact of Zeeman's coupling on the Fermi surface's topology in Na$_3$Bi in detail., Comment: Some typos are fixed

Published
2015

4. Time-Reversal Symmetry Breaking Driven Topological Phase Transition in EuB6

Author

Gao, Shun Ye, Xu, Sheng, Li, Hang, Yi, Chang Jiang, Nie, Si Min, Rao, Zhi Cheng, Wang, Huan, Hu, Quan Xin, Chen, Xue Zhi, Fan, Wen Hui, Huang, Jie Rui, Huang, Yao Bo, Pryds, Nini, Shi, Ming, Wang, Zhi Jun, Shi, You Guo, Xia, Tian Long, Qian, Tian, Ding, Hong, Gao, Shun Ye, Xu, Sheng, Li, Hang, Yi, Chang Jiang, Nie, Si Min, Rao, Zhi Cheng, Wang, Huan, Hu, Quan Xin, Chen, Xue Zhi, Fan, Wen Hui, Huang, Jie Rui, Huang, Yao Bo, Pryds, Nini, Shi, Ming, Wang, Zhi Jun, Shi, You Guo, Xia, Tian Long, Qian, Tian, and Ding, Hong

Abstract

The interplay between time-reversal symmetry (TRS) and band topology plays a crucial role in topological states of quantum matter. In time-reversal-invariant (TRI) systems, the inversion of spin-degenerate bands with opposite parity leads to nontrivial topological states, such as topological insulators and Dirac semimetals. When the TRS is broken, the exchange field induces spin splitting of the bands. The inversion of a pair of spin-splitting subbands can generate more exotic topological states, such as quantum anomalous Hall insulators and magnetic Weyl semimetals. So far, such topological phase transitions driven by the TRS breaking have not been visualized. In this work, using angle-resolved photoemission spectroscopy, we have demonstrated that the TRS breaking induces a band inversion of a pair of spin-splitting subbands at the TRI points of Brillouin zone in EuB6, when a long-range ferromagnetic order is developed. The dramatic changes in the electronic structure result in a topological phase transition from a TRI ordinary insulator state to a TRS-broken topological semimetal (TSM) state. Remarkably, the magnetic TSM state has an ideal electronic structure, in which the band crossings are located at the Fermi level without any interference from other bands. Our findings not only reveal the topological phase transition driven by the TRS breaking, but also provide an excellent platform to explore novel physical behavior in the magnetic topological states of quantum matter.

Published
2021

5. Time-Reversal Symmetry Breaking Driven Topological Phase Transition in EuB6

Author

Gao, Shun-Ye, primary, Xu, Sheng, additional, Li, Hang, additional, Yi, Chang-Jiang, additional, Nie, Si-Min, additional, Rao, Zhi-Cheng, additional, Wang, Huan, additional, Hu, Quan-Xin, additional, Chen, Xue-Zhi, additional, Fan, Wen-Hui, additional, Huang, Jie-Rui, additional, Huang, Yao-Bo, additional, Pryds, Nini, additional, Shi, Ming, additional, Wang, Zhi-Jun, additional, Shi, You-Guo, additional, Xia, Tian-Long, additional, Qian, Tian, additional, and Ding, Hong, additional

Published
2021
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6. Measurement of Superconductivity and Edge States in Topological Superconductor Candidate TaSe3.

Author

Liu, Shuai, Nie, Si-Min, Qi, Yan-Peng, Guo, Yan-Feng, Yuan, Hong-Tao, Yang, Le-Xian, Chen, Yu-Lin, Wang, Mei-Xiao, and Liu, Zhong-Kai

Subjects
*SUPERCONDUCTIVITY, *SUPERCONDUCTORS, *IRON-based superconductors, *ELECTRONIC density of states, *QUANTUM computing, *SCANNING tunneling microscopy
Abstract

Topological superconductors (TSCs) have been widely investigated in recent years due to their novel physics and ability to host Majorana fermions (MFs) which are key to topological quantum computation. Despite the great interest, only a few compounds have been proposed as candidates of intrinsic TSCs, such as iron-based superconductor FeSe0.55Te0.45 and 2M-WS2. Among them, quasi-one-dimensional superconductor TaSe3 possesses fascinating properties such as its simple stoichiometry, layered nature and chemical stability. Here, using scanning tunneling microscope/spectroscopy (STM/STS), we systematically investigate the topography and electronic structure of TaSe3. Our STM/STS measurement reveals large atomically flat, defect-free surfaces suitable for the search of MF; electronic density of states consistent with our angle-resolved photoemission result and band-structure calculations, and a uniform superconducting gap with a typical size of ∼ 0.25 meV. Remarkably, additional edge states are observed in the vicinity of the terrace edge, suggesting they may have a topological origin. Our result proves the coexistence of superconductivity and topological electronic structure in TaSe3, making it an intriguing platform to investigate topological superconductivity. [ABSTRACT FROM AUTHOR]

Published
2021
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7. Measurement of Superconductivity and Edge States in Topological Superconductor Candidate TaSe3.

Author

Liu, Shuai, Nie, Si-Min, Qi, Yan-Peng, Guo, Yan-Feng, Yuan, Hong-Tao, Yang, Le-Xian, Chen, Yu-Lin, Wang, Mei-Xiao, and Liu, Zhong-Kai

Subjects
SUPERCONDUCTIVITY, SUPERCONDUCTORS, IRON-based superconductors, ELECTRONIC density of states, QUANTUM computing, SCANNING tunneling microscopy
Abstract

Topological superconductors (TSCs) have been widely investigated in recent years due to their novel physics and ability to host Majorana fermions (MFs) which are key to topological quantum computation. Despite the great interest, only a few compounds have been proposed as candidates of intrinsic TSCs, such as iron-based superconductor FeSe0.55Te0.45 and 2M-WS2. Among them, quasi-one-dimensional superconductor TaSe3 possesses fascinating properties such as its simple stoichiometry, layered nature and chemical stability. Here, using scanning tunneling microscope/spectroscopy (STM/STS), we systematically investigate the topography and electronic structure of TaSe3. Our STM/STS measurement reveals large atomically flat, defect-free surfaces suitable for the search of MF; electronic density of states consistent with our angle-resolved photoemission result and band-structure calculations, and a uniform superconducting gap with a typical size of ∼ 0.25 meV. Remarkably, additional edge states are observed in the vicinity of the terrace edge, suggesting they may have a topological origin. Our result proves the coexistence of superconductivity and topological electronic structure in TaSe3, making it an intriguing platform to investigate topological superconductivity. [ABSTRACT FROM AUTHOR]

Published
2021
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