Topological light-trapping on a dislocation

Abstract

Topological insulators have unconventional gapless edge states where disorder-induced back-scattering is suppressed. In photonics, such edge states lead to unidirectional waveguides which are useful for integrated photonic circuitry. Cavity modes, another type of fundamental component in photonic chips, however, are not protected by band topology because of their lower dimensions. Here we demonstrate that concurrent wavevector space and real-space topology, dubbed as dual-topology, can lead to light-trapping in lower dimensions. The resultant photonic-bound state emerges as a Jackiw–Rebbi soliton mode localized on a dislocation in a two-dimensional photonic crystal, as proposed theoretically and discovered experimentally. Such a strongly confined cavity mode is found to be robust against perturbations. Our study unveils a mechanism for topological light-trapping in lower dimensions, which is invaluable for fundamental physics and various applications in photonics.

Recent Advances in the Metal‐Catalyzed Activation of Amide Bonds

“…Recently,Liand Szostak developed atransamidation reaction of N-Boc-activated amides with amines in the presence of LiHMDS( 3.0 equiv) as ab ase (Scheme 52). [105] Thisr eaction of-fered broad substrate scope and 75 examples were reported by using this method.…”

Active topological photonics

“…It is noteworthy is that the emergence of the topological modes is confirmed even when the period of 1D photonic crystal becomes only a few [67]. There are several physical interpretations for the emergence of the edge mode, such as those based on the presence of edge polarization associated with nontrivial Zak phase [55,68] and on a soliton formation process via the Jackiw-Rebbi mechanism [40,65,69]. According to M. Xiao et al, the current system can be viewed as a Fabry-Pérot resonator with zero cavity length [66].…”

“…They can function as nanocavities embedded in 2D systems, offering a natural platform for developing integrated photonic circuits. Meanwhile, one may consider the introduction of defect-based nanocavities into 2D topological photonic crystals by, for example, fulling some airholes with dielectric [64] or introducing topological disorder [65]. These types of cavities have been far less investigated in the context of topological photonics, despite their possibilities to function as high performance nanocavities in topological nanophotonic systems.…”

Data Denoising with transfer learning in single-cell transcriptomics

“…In scRNA-seq studies, technical noise blurs precise distinctions between cell states, and genes with 25 low expression cannot be accurately quantified. Existing methods [1][2][3][4][5][6] to denoise scRNA-seq data often 26 underperform when sequencing depth is low or when the cell type of interest is rare, and also ignore 27 datasets in public domain, which may contain relevant information to aid denoising. Ensuing the 28 mouse cell atlases 7,8 , we will soon have detailed atlases for each anatomic organ in the human body 9 .…”