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Photonic Topological Spin Hall Effect Mediated by Vortex Pairs
Bo Wang1, Elhanan Maguid1, Kexiu Rong1
1Micro and Nanooptics Laboratory, Faculty of Mechanical Engineering and Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 3200003, Israel.
Physical Review Letters
|January 18, 2020
Summary
We discovered a new topological mechanism for spin-dependent light transport using metasurfaces. This leads to photonic topological spin Hall and random Rashba effects, showing topology
Area of Science:
- Topological photonics
- Condensed matter physics
- Metasurface optics
Background:
- Topology has significantly advanced the understanding of physical phenomena.
- Spin-dependent photonic transport is crucial for advanced optical devices.
Purpose of the Study:
- To report a novel topological mechanism for spin-dependent photonic transport.
- To investigate the generation and properties of photonic topological defects.
Main Methods:
- Fabrication of 2D nanoantenna arrays (metasurfaces) with local deformations.
- Induction of Pancharatnam-Berry phase via random deformations.
- Observation of photonic topological defects, including bound vortex pairs and unbound vortices.
Main Results:
- Observed spin-dependent bound vortex pairs as the origin of the photonic topological spin Hall effect.
- Demonstrated subdiffraction-limited spin-split modes in momentum space.
- Observed spin-dependent unbound vortices inducing random spin-split modes (random Rashba effect).
Conclusions:
- The creation of bound and unbound vortices demonstrates a universal topological effect.
- The findings indicate the applicability of topological principles to various particle types.
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