You, J;
Lan, Z;
Bao, Q;
Panoiu, NC;
(2020)
Valley-Hall topological plasmons in a graphene nanohole plasmonic crystal waveguide.
IEEE Journal of Selected Topics in Quantum Electronics
10.1109/JSTQE.2020.2982991.
(In press).
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Abstract
We demonstrate that unidirectional and backscattering-immune propagation of terahertz optical waves can be achieved in a topological valley-Hall waveguide made of graphene nanohole plasmonic crystals. In order to gain deeper physical insights into these phenomena, the band diagram of graphene nanohole plamsonic crystals has been investigated and optimized. We found that a graphene plasmonic crystal with nanohole arrays belonging to the C6v symmetry group possesses gapless Dirac cones, which can be gapped out by introducing extra nanoholes such that the symmetry point group of the system is reduced from C6v to C3v. Taking advantage of this feature, we design a mirror symmetric domain-wall interface by placing together two optimized graphene plasmonic crystals so as to construct valley-polarized topological interface modes inside the opened bandgap. Our computational analysis shows that the valley-Hall topological domain-wall interface modes can be achieved at an extremely deep subwavelength scale, and do not rely on the application of external static magnetic fields. This work may pave a new way to develop highly-integrated and robust terahertz plasmonic waveguides at deep-subwavelength scale.
| Type: | Article |
|---|---|
| Title: | Valley-Hall topological plasmons in a graphene nanohole plasmonic crystal waveguide |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1109/JSTQE.2020.2982991 |
| Publisher version: | https://doi.org/10.1109/JSTQE.2020.2982991 |
| Language: | English |
| Additional information: | This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | Topological plasmon mode propagation, chirality-momentum locking, graphene plasmonic crystal waveguides, valley-Hall topological waveguides, domain-wall interface |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Electronic and Electrical Eng |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10094976 |
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