Multifrequency superscattering is a phenomenon in which the scattering cross section from a subwavelength object simultaneously exceeds the single-channel limit at multiple frequency regimes.Here,we achieve simultaneo...Multifrequency superscattering is a phenomenon in which the scattering cross section from a subwavelength object simultaneously exceeds the single-channel limit at multiple frequency regimes.Here,we achieve simultaneously,within a graphene-coated subwavelength structure,multifrequency superscattering and superscattering shaping with different engineered scattering patterns.It is shown that multimode degenerate resonances at multiple frequency regimes appearing in a graphene composite structure due to the peculiar dispersion can be employed to resonantly overlap electric and magnetic multipoles of various orders,and,as a result,effective multifrequency superscattering with different engineered angular patterns can be obtained.Moreover,the phenomena of multifrequency superscattering have a high tolerance to material losses and some structural variations.Our work should anticipate extensive applications ranging from emission enhancing,energy harvesting,and antenna design with improved sensitivity and accuracy due to multifrequency operation.展开更多
We propose a general method to realize a total scattering of an incident acoustic wave at interfaces between different media while allowing the flow of air, fluids and/or particles. This originates from the enlargemen...We propose a general method to realize a total scattering of an incident acoustic wave at interfaces between different media while allowing the flow of air, fluids and/or particles. This originates from the enlargement of the equivalent acoustic scattering cross section of an embedded object coated with acoustic metamaterials, which causes the coated object to behave as a scatterer bigger than its physical size. We theoretically design a model circular cylindrical object coated with such meta- materials whose properties are determined according to two different, but identical, methods. The desired function is confirmed for both far-field and near-field cases with full wave simulations based on the finite element method. This work reveals a promising way to achieve noise shielding and naval camouflage.展开更多
基金supported by the National Natural Science Foundation of China(Nos.11504306 and 92050102)Fujian Provincial Natural Science Foundation(No.2017J05015)。
文摘Multifrequency superscattering is a phenomenon in which the scattering cross section from a subwavelength object simultaneously exceeds the single-channel limit at multiple frequency regimes.Here,we achieve simultaneously,within a graphene-coated subwavelength structure,multifrequency superscattering and superscattering shaping with different engineered scattering patterns.It is shown that multimode degenerate resonances at multiple frequency regimes appearing in a graphene composite structure due to the peculiar dispersion can be employed to resonantly overlap electric and magnetic multipoles of various orders,and,as a result,effective multifrequency superscattering with different engineered angular patterns can be obtained.Moreover,the phenomena of multifrequency superscattering have a high tolerance to material losses and some structural variations.Our work should anticipate extensive applications ranging from emission enhancing,energy harvesting,and antenna design with improved sensitivity and accuracy due to multifrequency operation.
文摘We propose a general method to realize a total scattering of an incident acoustic wave at interfaces between different media while allowing the flow of air, fluids and/or particles. This originates from the enlargement of the equivalent acoustic scattering cross section of an embedded object coated with acoustic metamaterials, which causes the coated object to behave as a scatterer bigger than its physical size. We theoretically design a model circular cylindrical object coated with such meta- materials whose properties are determined according to two different, but identical, methods. The desired function is confirmed for both far-field and near-field cases with full wave simulations based on the finite element method. This work reveals a promising way to achieve noise shielding and naval camouflage.
