Observation of an unpaired photonic Dirac point
arXiv:1909.00351 · doi:10.1038/s41467-020-15801-z
Abstract
At photonic Dirac points, electromagnetic waves are governed by the same equations as two-component massless relativistic fermions. However, photonic Dirac points are known to occur in pairs in "photonic graphene" and other similar photonic crystals, which necessitates special precautions to excite only states near one of the Dirac points. Systems hosting unpaired photonic Dirac points are significantly harder to realize, as they require broken time-reversal symmetry. Here, we report on the first observation of an unpaired Dirac point in a planar two-dimensional photonic crystal. The structure incorporates gyromagnetic materials, which break time-reversal symmetry; the unpaired Dirac point occurs when a parity-breaking parameter is fine-tuned to a topological transition between a photonic Chern insulator and a conventional photonic insulator phase. Evidence for the unpaired Dirac point is provided by transmission and field-mapping experiments, including a demonstration of strongly non-reciprocal reflection. This photonic crystal is suitable for investigating the unique features of two-dimensional Dirac states, such as one-way Klein tunneling.
References in corpus (34)
- The electronic properties of graphene
- Two-Dimensional Gas of Massless Dirac Fermions in Graphene
- Experimental Observation of Quantum Hall Effect and Berry's Phase in Graphene
- Topological Insulators in Three Dimensions
- Chiral tunneling and the Klein paradox in graphene
- Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
- Topological Photonics
- Topological Photonics
- Photonic Floquet Topological Insulators
- Possible Realization of Directional Optical Waveguides in Photonic Crystals with Broken Time-Reversal Symmetry
- Experimental realisation of the topological Haldane model
- Valley filter and valley valve in graphene
- Andreev reflection and Klein tunneling in graphene
- Creating, moving and merging Dirac points with a Fermi gas in a tunable honeycomb lattice
- Evidence of Klein tunneling in graphene p-n junctions
- All-Si Valley-Hall Photonic Topological Insulator
- Topologically-protected refraction of robust kink states in valley photonic crystals
- Observation of photonic anomalous Floquet Topological Insulators
- Artificial graphene as a tunable Dirac material
- Experimental observation of anomalous topological edge modes in a slowly-driven photonic lattice
- Observation of novel edge states in photonic graphene
- Realization of a three-dimensional photonic topological insulator
- Three-dimensional topological photonic crystal with a single surface Dirac cone
- Observing Zitterbewegung for photons near the Dirac point of a two-dimensional photonic crystal
- Experimental observation of optical Weyl points
- Anomalous Topological Phases and Unpaired Dirac Cones in Photonic Floquet Topological Insulators
- Extremal transmission and beating effect of acoustic wave in two-dimensional sonic crystal
- Dirac-like plasmons in honeycomb lattices of metallic nanoparticles
- Scattering-Free Optical Edge States between Heterogeneous Photonic Topological Insulators
- Reconfigurable topological phases in next-nearest-neighbor coupled resonator lattices
- Photonic Anomalous Quantum Hall Effect
- Dirac Spectra and Edge States in Honeycomb Plasmonic Lattices
- Near-zero index magneto-optical medium realized with an unpaired Dirac point
- Spin and valley polarized one-way Klein tunneling in photonic topological insulators
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- A brief review of topological photonics in one, two, and three dimensions
- Observation of photonic antichiral edge states
- Hybrid topological photonic crystals
- Topological metasurface: From passive toward active and beyond
- Half-Quantized Hall Effect and Power Law Decay of Edge Current Distribution
- Photonic corner skin modes
- Observation of Dirac hierarchy in three-dimensional acoustic topological insulators
- Non-Abelian charged nodal links in dielectric photonic crystal
- Giant nonlocal edge conduction in the axion insulator state of MnBi2Te4
- Altermagnetism-Induced Parity Anomaly in Weak Topological Insulators
- Effective medium theory for photonic pseudospin-1/2 system
- Self-localized topological states in three dimensions
- Topological edge states in photonic Floquet insulator with unpaired Dirac cones
- Band alignment effect in the topological photonic alloy
- Topological Singularities in Metasurface Scattering Matrices: From Nodal Lines to Exceptional Lines
- Twist Angle, Strain, Corrugation and Moire Unit cell in Twisted Bilayer Graphene