Breakdown of spin-to-helicity locking at the nanoscale in topological photonic crystal edge states
arXiv:2202.04402 · doi:10.1103/PhysRevLett.128.203903
Abstract
We measure the local near-field spin in topological edge state waveguides that emulate the quantum spin Hall effect. We reveal a highly structured spin density distribution that is not linked to a unique pseudospin value. From experimental near-field real-space maps and numerical calculations, we confirm that this local structure is essential in understanding the properties of optical edge states and light-matter interactions. The global spin is reduced by a factor of 30 in the near field and, for certain frequencies, flipped compared to the pseudospin measured in the far-field. We experimentally reveal the influence of higher-order Bloch harmonics in spin inhomogeneity, leading to a breakdown in the coupling between local helicity and global spin.
arXiv comment6 pages, 5 figures, 50 references
References in corpus (29)
- Topological Insulators
- Spin-orbit interactions of light
- Scheme to Achieve Silicon Topological Photonics
- Robust optical delay lines via topological protection
- Reflection-Free One-Way Edge Modes in a Gyromagnetic Photonic Crystal
- Transverse and longitudinal angular momenta of light
- Lasing in topological edge states of a 1D lattice
- Quantum spin Hall effect of light
- Chiral nanophotonic waveguide interface based on spin-orbit coupling of light
- A topological quantum optics interface
- All-Si Valley-Hall Photonic Topological Insulator
- Deterministic photon-emitter coupling in chiral photonic circuits
- A Silicon-on-Insulator Slab for Topological Valley Transport
- Visualization of unidirectional optical waveguide using topological photonic crystals made of dielectric material
- Quantum Optics of Chiral Spin Networks
- Nanoscale optical positioning of single quantum dots for bright and pure single-photon emission
- Universal spin-momentum locking of evanescent waves
- Chirality of nanophotonic waveguide with embedded quantum emitter for unidirectional spin transfer
- Two-Dimensionally Confined Topological Edge States in Photonic Crystals
- Transverse spin and momentum in two-wave interference
- Photonic Quantum Circuits with Time Delays
- Polarization engineering in photonic crystal waveguides for spin-photon entanglers
- Accidental degeneracy and topological phase transitions in two-dimensional core-shell dielectric photonic crystals
- Quantum networks with chiral light--matter interaction in waveguides
- A perspective on topological nanophotonics: current status and future challenges
- Deterministic positioning of nanophotonic waveguides around single self-assembled quantum dots
- Exciting Pseudospin Dependent Edge States in Plasmonic Metasurfaces
- Transverse angular momentum in topological photonic crystals
- Near- and Far-Field Excitation of Topological Plasmonic Metasurfaces