Nonreciprocal wide-angle bidirectional absorber based on one-dimensional magnetized gyromagnetic photonic crystals

We propose magnetized gyromagnetic photonic crystals(MGPCs)composed of indium antimonide(InSb)and yttrium iron garnet ferrite(YIGF)layers,which possess the properties of nonreciprocal wide-angle bidirectional absorption.Periodical defects in the MGPCs work as filters.Absorption bands(ABs)for the positive and negative propagations arise from the optical Tamm state and resonance in cavities respectively,and they prove to share no overlaps in the studied frequency range.Givenω=2.0138 THz,for the positive propagation,the ABs in the high-frequency range are localized in the interval between 0.66ωand 0.88ω.In the angular range,the ABs for the TE and TM waves reach 60°and 51°,separately.For the negative propagation,the ABs in the low-frequency range are localized in the interval between 0.13ωand 0.3ω.The AB s extend to 60°for the TE waves and 80.4°for the TM waves.There also exists a narrow frequency band in a lower frequency range.The relevant factors,which include the external temperature,the magnetic fields applied to the YIGF,the refractive index of the impedance matching layer,and the defect thickness,are adjusted to investigate the effects on the ABs.All the numerical simulations are based on the transfer matrix method.This work provides an approach to designs of isolators and so on.

Topological photonic states in gyromagnetic photonic crystals:Physics,properties,and applications

Topological photonic states(TPSs)as a new type of waveguide state with one-way transport property can resist backscattering and are impervious to defects,disorders and metallic obstacles.Gyromagnetic photonic crystal(GPC)is the first artificial microstructure to implement TPSs,and it is also one of the most important platforms for generating truly one-way TPSs and exploring their novel physical properties,transport phenomena,and advanced applications.Herein,we present a brief review of the fundamental physics,novel properties,and practical applications of TPSs based on GPCs.We first examine chiral one-way edge states existing in uniformly magnetized GPCs of ordered and disordered lattices,antichiral one-way edge states in cross magnetized GPCs,and robust one-way bulk states in heterogeneously magnetized GPCs.Then,we discuss the strongly coupling effect between two co-propagating(or counter-propagating)TPSs and the resulting physical phenomena and device applications.Finally,we analyze the key issues and prospect the future development trends for TPSs in GPCs.The purpose of this brief review is to provide an overview of the main features of TPSs in GPC systems and offer a useful guidance and motivation for interested scientists and engineers working in related scientific and technological areas.

Type-Ⅱ Weyl points and one-way interface transmission in a three-dimensional gyromagnetic photonic crystal

One-dimensional(1D)one-way waveguides based on topological edge states of two-dimensional(2D)gyromagnetic photonic crystals have been studied extensively.Here,we theoretically propose a three-dimensional(3D)all-dielectric gyromagnetic photonic crystal with type-Ⅱ Weyl points.Based on the inclined band properties of the type-Ⅱ Weyl surface states,we design a 2D one-way interface transmission channel on the Weyl crystal.Light waves in such 2D waveguides can be transmitted robustly over metal obstacles almost without any back-reflection,topologically protected by the type-Ⅱ Weyl points.By manipulating the magnetic field or structural parameters,we also achieve the topological phase transition between Weyl phase and 3D Chern insulator phase and obtain the corresponding phase diagram,which provides more possibilities for topological regulation of the surface states.This work suggests a new way to construct unidirectional 2D waveguides with larger area of energy transmission in 3D space,which is a promising platform for developing 3D topological photonic devices.

Unidirectional electromagnetic windmill scattering in a magnetized gyromagnetic cylinder

We present a discovery of an unusual unidirectionally rotating windmill scattering of electromagnetic waves by a magnetized gyromagnetic cylinder via an analytical theory for rigorous solution to fields and charges and an understanding of the underlying mathematical and physical mechanisms. Mathematically, the generation of nonzero off-diagonal components can break the symmetry of forward and backward scattering coefficients, producing unidirectional windmill scattering. Physically, this windmill scattering originates from the nonreciprocal unidirectional rotation of polarized magnetic charges on the surface of a magnetized gyromagnetic cylinder, which drives the scattering field to radiate outward in the radial direction and unidirectionally emit in the tangential direction. Interestingly, the unidirectional electromagnetic windmill scattering is insensitive to the excitation direction. Moreover, we also discuss the size dependence of unidirectional windmill scattering by calculating the scattering spectra of the gyromagnetic cylinder. These results are helpful for exploring and understanding novel interactions between electromagnetic waves and gyromagnetic materials or structures and offer deep insights for comprehending topological photonic states in gyromagnetic systems from the aspect of fundamental classical electrodynamics and electromagnetics.

Reciprocity as an Ever-Present Dual Property of Everything

Reciprocity may be understood as relation of action and reaction in the sense of Hegel’s philosophical definition. Quoting Kant, freedom and ethical necessities are reciprocally limited. In this contribution, a more mathematical than philosophical reflection about reciprocity as an ever-present dual property of everything was given. As a crystallographer, the author is familiar with the action of Fourier transforms and the relation between a crystal lattice and its reciprocal lattice, already pointing to the duality between particles and waves. A generalization of the reciprocity term was stimulated by results of the famous Information Relativity (IR) theory of Suleiman with its proven physical manifestation of matter-wave duality, compared to the set-theoretical E-Infinity theory developed by El Naschie, where the zero set represents the pre-quantum particle, and the pre-quantum wave is assigned to the empty set boundary surrounding the pre-particle. Expectedly, the most irrational number of the golden mean is involved in these thoughts, because this number is intimately connected with its inverse. An important role plays further Hardy’s maximum quantum entanglement probability as the fifth power of φand its connection to the dark matter. Remembering, the eleven dimensions in Witten’s M-theory may be decomposed into the Lucas number L5 = 11 = φ−5 – φ5. Reciprocity is indeed omnipresent in our world as piloting waves that accompany all observable earthen and cosmic matter. As a side effect of the IR theory some fundamental constants such as the gyromagnetic factor of the electron, Sommerfeld’s fine-structure constant as well as the charge of the electron must be marginally changed caused by altered relativistic corrections. Consequences also arise for our vision about the evolution of life and consciousness.

Mass Constituents of a Flat Lattice Multiverse: Conclusion from Similarity between Two Universal Numbers, the Rocksalt-Type 2<i>D</i>Madelung Constant and the Golden Mean

In fairly good agreement with the consensus range of dark energy to matter this ratio of the critical density is suggested to be connected with the golden mean &phi;=0.6180339887, yielding for dark energy to matter mass fractions .?Assuming the baryonic matter to be only 4.432%, the ratio of matter to baryonic matter would be , and further the ratio of dark matter to baryonic one . If one subtracts from the dark matter a contribution of antimatter with the same mass of baryonic matter, according to the antigravity theories of Villata respectively Hajdukovic, the remaining mass ratio would yield . Replacing the “Madelung” constant α of Villata’s “lattice universe” by &phi;, one reaches again 1 + &phi;as the ratio of the repulsive mass contribution to the attractive one. Assuming instead of a 3D lattice a flat 2D one of rocksalt type, the numerical similarity between the Madelung constant and φ&minus;1 could not be just coincidence. The proposed scaling of the cosmological mass fractions with the square of the most irrational universal number &phi;may indicate that the chaotic cosmological processes have reached a quite stable equilibrium. This may be confirmed by another, but similar representation of the mass constituents by the Archimedes’ constant &pi;, giving for respectively for the dark components . However, the intimate connection of φ with its reciprocal may ignite the discussion whether our universe is intertwined with another universe or even part of a multiverse with the dark constituents contributed from there.

Comment to Guynn’s Fine-Structure Constant Approach

Sommerfeld’s fundamental fine-structure constant α once more gives reason to be amazed. This comment is a Chapter of a publication in preparation dealing mainly with golden ratio signature behind Preston Guynn’s famous matter/space approach. As a result we present a relation of α to the galactic velocity , mediated by the circle constant π, which points to an omnipresent importance of this constant and its intrinsic reciprocity pecularity: α ≈ π2|βg| respectively . The designation fine-structure constant should be replaced simply by Sommerfeld’s constant. We present golden mean-based approximations for α as well as for electron’s charge and mass and connect the word average value of interaction coupling constant αs(mz) with |βg|.