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.
Original language | English |
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Article number | 203903 |
Number of pages | 6 |
Journal | Physical Review Letters |
Volume | 128 |
Issue number | 20 |
DOIs | |
Publication status | Published - 2022 |
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Dive into the research topics of 'Breakdown of Spin-to-Helicity Locking at the Nanoscale in Topological Photonic Crystal Edge States'. Together they form a unique fingerprint.Datasets
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Data underlying the publication and chapter 3: Breakdown of spin-to-helicity locking at the nanoscale in topological photonic crystal edge states
Arora, S. (Creator), Bauer, T. A. (Creator), Barczyk, R. T. (Creator), Verhagen, E. (Creator) & Kuipers, L. (Creator), TU Delft - 4TU.ResearchData, 24 Jul 2023
DOI: 10.4121/18779327
Dataset/Software: Dataset
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PhD dissertation
Arora, S. (Creator), TU Delft - 4TU.ResearchData, 13 Jul 2023
DOI: 10.4121/F91DD6C6-3125-445E-A933-6A0BA5C5DA0E
Dataset/Software: Dataset