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Open AccessFlat bands, sharp physics
Flat bands arise in periodic media when symmetries or fine-tuning result in perfect wavepacket localisation. Flat band localisation is fragile and exhibits remarkably sharp sensitivity to perturbations includi...
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Open AccessFock state-enhanced expressivity of quantum machine learning models
The data-embedding process is one of the bottlenecks of quantum machine learning, potentially negating any quantum speedups. In light of this, more effective data-encoding strategies are necessary. We propose ...
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Probing bulk topological invariants using leaky photonic lattices
Topological invariants characterizing filled Bloch bands underpin electronic topological insulators and analogous artificial lattices for Bose–Einstein condensates, photonics and acoustic waves. In bosonic sys...
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Open AccessSpecial Issue on “Topological photonics and beyond: novel concepts and recent advances”
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Open AccessNontrivial coupling of light into a defect: the interplay of nonlinearity and topology
The flourishing of topological photonics in the last decade was achieved mainly due to developments in linear topological photonic structures. However, when nonlinearity is introduced, many intriguing question...
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Open AccessUniversal momentum-to-real-space map** of topological singularities
Topological properties of materials are typically presented in momentum space. Here, we demonstrate a universal map** of topological singularities from momentum to real space. By exciting Dirac-like cones in...
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Open AccessTopological non-Hermitian origin of surface Maxwell waves
Maxwell electromagnetism, describing the wave properties of light, was formulated 150 years ago. More than 60 years ago it was shown that interfaces between optical media (including dielectrics, metals, negati...
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Nonreciprocity in synthetic photonic materials with nonlinearity
Synthetic photonic materials created by engineering the profile of refractive index or gain/loss distribution, such as negative-index metamaterials or parity-time-symmetric structures, can exhibit electric and...
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Open AccessObservation of transverse coherent backscattering in disordered photonic structures
Coherent backscattering, also referred to as weak localization, is an exciting multidisciplinary phenomenon that appears in disordered systems of multiple coherent-wave scattering. Providing proper scattering ...
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Experimental observation of optical Weyl points and Fermi arc-like surface states
Weyl fermions are hypothetical two-component massless relativistic particles in three-dimensional (3D) space, proposed by Hermann Weyl in 1929. Their band-crossing points, called ‘Weyl points’, carry a topolog...
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Localization of weakly disordered flat band states
Certain tight binding lattices host macroscopically degenerate flat spectral bands. Their origin is rooted in local symmetries of the lattice, with destructive interference leading to the existence of compact...
