Topological insulators, an interesting research topic in physics, have greatly improved our understanding of the classification of states in condensed matter physics. Inspired by the topological properties of electronic band structures, scientists designed a photonic counterpart and observed the charming photonic edge states in the artificial photonic structures. It is of great scientific significance to use topology to control the motion of photons. Photonic topological edge states can overcome the scattering losses caused by structural defects and disorders and realize topologically protected photonic devices, such as unidirectional waveguides and single-mode lasers. Non-Hermitian topological photonics is a very interesting research topic in topological physics. Advances in the field of non-Hermitian photonics based on parity-time (PT) symmetry or anisotropic coupling distributions have greatly improved the ability to design new photonic topological insulators in previously inaccessible ways. Overall, the topological non-Hermitian systems provide an effective avenue for studying the intriguing properties of topological photonics involving exceptional points (EPs) and novel skin effect, and developing new functional devices.
Non-Hermitian and topological metamaterials have unprecedented capabilities to manipulate electromagnetic waves and many potential applications. Thus far, robustness, active control, and broadband are the main pursuit of meta-photonics. Non-Hermitian topological structures with anisotropic coupling present the topological skin effect whose local characteristic of robustness edge states is independent of the working frequency. Very recently, with the development of absorption EPs, the non-Hermitian properties controlled by the external excitation provide a new way to study the phase transition. In addition, tuning the non-Hermitian and topological properties in metasurfaces has gained significant interest of late because of its usefulness in the design of planar devices that are easier to integrate and has a smaller loss.
We invite the submission of Original Research, Review, Mini Review, and Perspective articles on themes including, but not limited to:
• Topological properties of zero-index metamaterials, hyperbolic metamaterials, and chiral metamaterials;
• Exceptional state transfer and geometric phase in the Riemann sheets;
• Non-Abelian braiding and non-Abelian Thouless pumping;
• Topological states in hyperbolic lattices with non-Euclidean geometry;
• Complex topological bands, such as Mobius ring and Klein bottle;
• Coherent perfect absorption (CPA) controlled by the resonant EPs and absorption EPs;
• Exceptional lines and surfaces in the non-Hermitian system with PT or anti-PT symmetry;
• Topological skin effect and the delocalization in the non-Hermitian topological structures;
• Bound state in the continuum and topological charges control in the non-Hermitian structures;
• High-dimensional, synthetic dimensional, and high-order non-Hermitian topological structures;
• Quasi-periodic, fractal, and disordered non-Hermitian topological structures;
• Classification and designing of topological photonics by machine learning;
• Twist-optics in Moiré non-Hermitian and topological structures;
• Non-Hermitian and/or topological devices, including sensors, wireless power transfer, and antennas;
• Other related topological and non-Hermitian areas: circuits, acoustics, elastic, and heat.
Topological insulators, an interesting research topic in physics, have greatly improved our understanding of the classification of states in condensed matter physics. Inspired by the topological properties of electronic band structures, scientists designed a photonic counterpart and observed the charming photonic edge states in the artificial photonic structures. It is of great scientific significance to use topology to control the motion of photons. Photonic topological edge states can overcome the scattering losses caused by structural defects and disorders and realize topologically protected photonic devices, such as unidirectional waveguides and single-mode lasers. Non-Hermitian topological photonics is a very interesting research topic in topological physics. Advances in the field of non-Hermitian photonics based on parity-time (PT) symmetry or anisotropic coupling distributions have greatly improved the ability to design new photonic topological insulators in previously inaccessible ways. Overall, the topological non-Hermitian systems provide an effective avenue for studying the intriguing properties of topological photonics involving exceptional points (EPs) and novel skin effect, and developing new functional devices.
Non-Hermitian and topological metamaterials have unprecedented capabilities to manipulate electromagnetic waves and many potential applications. Thus far, robustness, active control, and broadband are the main pursuit of meta-photonics. Non-Hermitian topological structures with anisotropic coupling present the topological skin effect whose local characteristic of robustness edge states is independent of the working frequency. Very recently, with the development of absorption EPs, the non-Hermitian properties controlled by the external excitation provide a new way to study the phase transition. In addition, tuning the non-Hermitian and topological properties in metasurfaces has gained significant interest of late because of its usefulness in the design of planar devices that are easier to integrate and has a smaller loss.
We invite the submission of Original Research, Review, Mini Review, and Perspective articles on themes including, but not limited to:
• Topological properties of zero-index metamaterials, hyperbolic metamaterials, and chiral metamaterials;
• Exceptional state transfer and geometric phase in the Riemann sheets;
• Non-Abelian braiding and non-Abelian Thouless pumping;
• Topological states in hyperbolic lattices with non-Euclidean geometry;
• Complex topological bands, such as Mobius ring and Klein bottle;
• Coherent perfect absorption (CPA) controlled by the resonant EPs and absorption EPs;
• Exceptional lines and surfaces in the non-Hermitian system with PT or anti-PT symmetry;
• Topological skin effect and the delocalization in the non-Hermitian topological structures;
• Bound state in the continuum and topological charges control in the non-Hermitian structures;
• High-dimensional, synthetic dimensional, and high-order non-Hermitian topological structures;
• Quasi-periodic, fractal, and disordered non-Hermitian topological structures;
• Classification and designing of topological photonics by machine learning;
• Twist-optics in Moiré non-Hermitian and topological structures;
• Non-Hermitian and/or topological devices, including sensors, wireless power transfer, and antennas;
• Other related topological and non-Hermitian areas: circuits, acoustics, elastic, and heat.