Quantum Hall and Light Responses in a 2D Topological Semimetal
We have recently identified a protected topological semimetal in graphene which presents a zero-energy edge mode robust to disorder and interactions. Here, we address the characteristics of this semimetal and show that the $\mathbb{Z}$ topological invariant of the Hall conductivity associated to the...
Saved in:
| Main Authors: | , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Académie des sciences
2024-12-01
|
| Series: | Comptes Rendus. Physique |
| Subjects: | |
| Online Access: | https://comptes-rendus.academie-sciences.fr/physique/articles/10.5802/crphys.202/ |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1825205742066466816 |
|---|---|
| author | Le Hur, Karyn Al Saati, Sariah |
| author_facet | Le Hur, Karyn Al Saati, Sariah |
| author_sort | Le Hur, Karyn |
| collection | DOAJ |
| description | We have recently identified a protected topological semimetal in graphene which presents a zero-energy edge mode robust to disorder and interactions. Here, we address the characteristics of this semimetal and show that the $\mathbb{Z}$ topological invariant of the Hall conductivity associated to the lowest energy band can be equivalently measured from the resonant response to circularly polarized light resolved at the Dirac points. The (non-quantized) conductivity responses of the intermediate energy bands, including the Fermi surface, also give rise to a $\mathbb{Z}$2 invariant. We emphasize on the bulk-edge correspondence as a protected topological half metal, i.e. one spin-population polarized in the plane is in the insulating phase related to the robust edge mode while the other is in the metallic regime. The quantized transport at the edges is equivalent to a $\frac{1}{2}-\frac{1}{2}$ conductance for spin polarizations along z direction. We also build a parallel between the topological Hall response and a pair of half numbers (half Skyrmions) through the light response locally resolved in momentum space and on the sphere. |
| format | Article |
| id | doaj-art-f7468d03cba94ab5955b470661549ed5 |
| institution | Kabale University |
| issn | 1878-1535 |
| language | English |
| publishDate | 2024-12-01 |
| publisher | Académie des sciences |
| record_format | Article |
| series | Comptes Rendus. Physique |
| spelling | doaj-art-f7468d03cba94ab5955b470661549ed52025-02-07T13:53:46ZengAcadémie des sciencesComptes Rendus. Physique1878-15352024-12-0125G141543210.5802/crphys.20210.5802/crphys.202Quantum Hall and Light Responses in a 2D Topological SemimetalLe Hur, Karyn0https://orcid.org/0000-0002-3990-4782Al Saati, Sariah1https://orcid.org/0000-0002-9524-8687CPHT, CNRS, Institut Polytechnique de Paris, Route de Saclay, 91120 Palaiseau, FranceCPHT, CNRS, Institut Polytechnique de Paris, Route de Saclay, 91120 Palaiseau, FranceWe have recently identified a protected topological semimetal in graphene which presents a zero-energy edge mode robust to disorder and interactions. Here, we address the characteristics of this semimetal and show that the $\mathbb{Z}$ topological invariant of the Hall conductivity associated to the lowest energy band can be equivalently measured from the resonant response to circularly polarized light resolved at the Dirac points. The (non-quantized) conductivity responses of the intermediate energy bands, including the Fermi surface, also give rise to a $\mathbb{Z}$2 invariant. We emphasize on the bulk-edge correspondence as a protected topological half metal, i.e. one spin-population polarized in the plane is in the insulating phase related to the robust edge mode while the other is in the metallic regime. The quantized transport at the edges is equivalent to a $\frac{1}{2}-\frac{1}{2}$ conductance for spin polarizations along z direction. We also build a parallel between the topological Hall response and a pair of half numbers (half Skyrmions) through the light response locally resolved in momentum space and on the sphere.https://comptes-rendus.academie-sciences.fr/physique/articles/10.5802/crphys.202/Topological systemsSemimetalsHall conductivityResponse to circular light |
| spellingShingle | Le Hur, Karyn Al Saati, Sariah Quantum Hall and Light Responses in a 2D Topological Semimetal Comptes Rendus. Physique Topological systems Semimetals Hall conductivity Response to circular light |
| title | Quantum Hall and Light Responses in a 2D Topological Semimetal |
| title_full | Quantum Hall and Light Responses in a 2D Topological Semimetal |
| title_fullStr | Quantum Hall and Light Responses in a 2D Topological Semimetal |
| title_full_unstemmed | Quantum Hall and Light Responses in a 2D Topological Semimetal |
| title_short | Quantum Hall and Light Responses in a 2D Topological Semimetal |
| title_sort | quantum hall and light responses in a 2d topological semimetal |
| topic | Topological systems Semimetals Hall conductivity Response to circular light |
| url | https://comptes-rendus.academie-sciences.fr/physique/articles/10.5802/crphys.202/ |
| work_keys_str_mv | AT lehurkaryn quantumhallandlightresponsesina2dtopologicalsemimetal AT alsaatisariah quantumhallandlightresponsesina2dtopologicalsemimetal |