Lorentz-violating type-II Dirac fermions in full-Heusler compounds XMg2Ag (X = Pr, Nd, Sm)
Lorentz-violating type-II Dirac fermion, as a new type of quasiparticles beyond the high-energy physics, has received intense attention recently. However, excellent candidate materials which contain sufficiently more type-II Dirac points near the Fermi level are still in scarcity. Here, we report a...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2020-01-01
|
| Series: | New Journal of Physics |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1367-2630/ab9d55 |
| _version_ | 1797750438135595008 |
|---|---|
| author | Weizhen Meng Xiaoming Zhang Ying Liu Xuefang Dai Guodong Liu |
| author_facet | Weizhen Meng Xiaoming Zhang Ying Liu Xuefang Dai Guodong Liu |
| author_sort | Weizhen Meng |
| collection | DOAJ |
| description | Lorentz-violating type-II Dirac fermion, as a new type of quasiparticles beyond the high-energy physics, has received intense attention recently. However, excellent candidate materials which contain sufficiently more type-II Dirac points near the Fermi level are still in scarcity. Here, we report a family of existing full-Heusler compounds, namely XMg _2 Ag (X = Pr, Nd, Sm), can serve as excellent Lorentz-violating type-II Dirac semimetals. We find they show several symmetry-protected nodal loops and triply degenerate nodal points (TDNPs) when spin–orbit coupling (SOC) is not considered. These fermions show clear nontrivial surface states. When SOC is included, the TDNPs transform into type-II Dirac points, characterized by Fermi arc surface states. The type-II DPs are protected by the C _4 _v symmetry in the Γ– X path. Comparing with other type-II Dirac semimetals, XMg _2 Ag compounds have additional advantages including: (i) they contain as much as three pairs of type-II Dirac points; (ii) all the Dirac points locate very close to the Fermi level. These advantages make XMg _2 Ag compounds are suitable for studying the novel properties of type-II Dirac fermions in future experiments. |
| first_indexed | 2024-03-12T16:32:42Z |
| format | Article |
| id | doaj.art-ae56fb1eb3234df194d9c366e7950ce4 |
| institution | Directory Open Access Journal |
| issn | 1367-2630 |
| language | English |
| last_indexed | 2024-03-12T16:32:42Z |
| publishDate | 2020-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | New Journal of Physics |
| spelling | doaj.art-ae56fb1eb3234df194d9c366e7950ce42023-08-08T15:24:23ZengIOP PublishingNew Journal of Physics1367-26302020-01-0122707306110.1088/1367-2630/ab9d55Lorentz-violating type-II Dirac fermions in full-Heusler compounds XMg2Ag (X = Pr, Nd, Sm)Weizhen Meng0https://orcid.org/0000-0001-6044-1738Xiaoming Zhang1https://orcid.org/0000-0001-7225-2774Ying Liu2https://orcid.org/0000-0003-1207-4923Xuefang Dai3Guodong Liu4School of Materials Science and Engineering, Hebei University of Technology , Tianjin 300130, People’s Republic of ChinaSchool of Materials Science and Engineering, Hebei University of Technology , Tianjin 300130, People’s Republic of ChinaSchool of Materials Science and Engineering, Hebei University of Technology , Tianjin 300130, People’s Republic of China; Research Laboratory for Quantum Materials, Singapore University of Technology and Design , Singapore 487372, SingaporeSchool of Materials Science and Engineering, Hebei University of Technology , Tianjin 300130, People’s Republic of ChinaSchool of Materials Science and Engineering, Hebei University of Technology , Tianjin 300130, People’s Republic of China; School of Physics and Electronic Engineering, Chongqing Normal University , Chongqing 400044, ChinaLorentz-violating type-II Dirac fermion, as a new type of quasiparticles beyond the high-energy physics, has received intense attention recently. However, excellent candidate materials which contain sufficiently more type-II Dirac points near the Fermi level are still in scarcity. Here, we report a family of existing full-Heusler compounds, namely XMg _2 Ag (X = Pr, Nd, Sm), can serve as excellent Lorentz-violating type-II Dirac semimetals. We find they show several symmetry-protected nodal loops and triply degenerate nodal points (TDNPs) when spin–orbit coupling (SOC) is not considered. These fermions show clear nontrivial surface states. When SOC is included, the TDNPs transform into type-II Dirac points, characterized by Fermi arc surface states. The type-II DPs are protected by the C _4 _v symmetry in the Γ– X path. Comparing with other type-II Dirac semimetals, XMg _2 Ag compounds have additional advantages including: (i) they contain as much as three pairs of type-II Dirac points; (ii) all the Dirac points locate very close to the Fermi level. These advantages make XMg _2 Ag compounds are suitable for studying the novel properties of type-II Dirac fermions in future experiments.https://doi.org/10.1088/1367-2630/ab9d55full-Heusler alloytype-II Dirac semimetalsnodal-line semimetals |
| spellingShingle | Weizhen Meng Xiaoming Zhang Ying Liu Xuefang Dai Guodong Liu Lorentz-violating type-II Dirac fermions in full-Heusler compounds XMg2Ag (X = Pr, Nd, Sm) New Journal of Physics full-Heusler alloy type-II Dirac semimetals nodal-line semimetals |
| title | Lorentz-violating type-II Dirac fermions in full-Heusler compounds XMg2Ag (X = Pr, Nd, Sm) |
| title_full | Lorentz-violating type-II Dirac fermions in full-Heusler compounds XMg2Ag (X = Pr, Nd, Sm) |
| title_fullStr | Lorentz-violating type-II Dirac fermions in full-Heusler compounds XMg2Ag (X = Pr, Nd, Sm) |
| title_full_unstemmed | Lorentz-violating type-II Dirac fermions in full-Heusler compounds XMg2Ag (X = Pr, Nd, Sm) |
| title_short | Lorentz-violating type-II Dirac fermions in full-Heusler compounds XMg2Ag (X = Pr, Nd, Sm) |
| title_sort | lorentz violating type ii dirac fermions in full heusler compounds xmg2ag x pr nd sm |
| topic | full-Heusler alloy type-II Dirac semimetals nodal-line semimetals |
| url | https://doi.org/10.1088/1367-2630/ab9d55 |
| work_keys_str_mv | AT weizhenmeng lorentzviolatingtypeiidiracfermionsinfullheuslercompoundsxmg2agxprndsm AT xiaomingzhang lorentzviolatingtypeiidiracfermionsinfullheuslercompoundsxmg2agxprndsm AT yingliu lorentzviolatingtypeiidiracfermionsinfullheuslercompoundsxmg2agxprndsm AT xuefangdai lorentzviolatingtypeiidiracfermionsinfullheuslercompoundsxmg2agxprndsm AT guodongliu lorentzviolatingtypeiidiracfermionsinfullheuslercompoundsxmg2agxprndsm |