Metasurfaces and metagratings offer new platforms for electromagnetic wave control with significant responses.However,metasurfaces based on abrupt phase change and resonant structures suffer from the drawback of high ...Metasurfaces and metagratings offer new platforms for electromagnetic wave control with significant responses.However,metasurfaces based on abrupt phase change and resonant structures suffer from the drawback of high loss and face challenges when applied in water waves.Therefore,the application of metasurfaces in water wave control is not ideal due to the limitations associated with high loss and other challenges.We have discovered that non-resonant metagratings exhibit promising effects in water wave control.Leveraging the similarity between bridges and metagratings,we have successfully developed a water wave metagrating model inspired by the ancient Luoyang Bridge in China.We conduct theoretical calculations and simulations on the metagrating and derive the equivalent anisotropic model of the metagrating.This model provides evidence that the metagrating has the capability to control water waves and achieve unidirectional surface water wave.The accuracy of our theory is strongly supported by the clear observation of the unidirectional propagation phenomenon during simulation and experiments conducted using a reduced version of the metagrating.It is the first time that the unidirectional propagation of water waves has been seen in water wave metagrating experiment.Above all,we realize the water wave metagrating experiment for the first time.By combining complex gratings with real bridges,we explore the physics embedded in the ancient building—Luoyang Bridge,which are of great significance for the water wave metagrating design and provide a new method for analyzing the effects of water waves on bridges.At the same time,this discovery also provides a new idea for ocean cargo transportation,ocean garbage cleaning,and the development and protection of ancient bridges.展开更多
Ferrimagnetic materials exhibiting remanence can be used to achieve unidirectional electromagnetic-field propagation in the form of magnetoplasmons(MPs)in the subwavelength regime.This study investigates the MP proper...Ferrimagnetic materials exhibiting remanence can be used to achieve unidirectional electromagnetic-field propagation in the form of magnetoplasmons(MPs)in the subwavelength regime.This study investigates the MP properties and various guiding modes in a hollow cylindrical waveguide made of materials that exhibit remanence.Pattern analysis and numerical simulations are used to demonstrate that dispersion relationships and electromagnetic-field distribution are strongly affected by the operating frequency and physical dimensions of the structure.In addition,the existence of two different guiding modes is proved,namely regular and surface-wave modes.By adjusting the operating frequency and reducing the diameter of the hollow cylinder,the regular mode can be suppressed so as to only retain the surface-wave mode,which enables unidirectional MP propagation in the cylindrical waveguide.Moreover,the unidirectional surface-wave mode is robust to backscattering due to surface roughness and defects,which makes it very useful for application in field-enhancement devices.展开更多
Optical non-reciprocity is a fundamental phenomenon in photonics.It is crucial for developing devices that rely on directional signal control,such as optical isolators and circulators.However,most research in this fie...Optical non-reciprocity is a fundamental phenomenon in photonics.It is crucial for developing devices that rely on directional signal control,such as optical isolators and circulators.However,most research in this field has focused on systems in equilibrium or steady states.In this work,we demonstrate a room-temperature Rydberg atomic platform where the unidirectional propagation of light acts as a switch to mediate time-crystalline-like collective oscillations through atomic synchronization.展开更多
Photonic structures with topological edge states and resonance loops are both important in optical communication systems,but they are usually two separate structures.In order to obtain a photonic system combining prop...Photonic structures with topological edge states and resonance loops are both important in optical communication systems,but they are usually two separate structures.In order to obtain a photonic system combining properties from both,we design multiple-layer nested photonic topological structures.The nested topological loops not only have topological protection immune to structural disorder and defects,but also possess both the properties of unidirectional propagation and loop resonance.Through mode analysis and simulations,we find that the transport can form diverse circulation loops.Each loop has its own resonance frequencies and can be solely excited in the nested layered structure through choosing its resonance frequencies.As a result,this work shows great application prospects in the area of reconfigurable photonic circuits.展开更多
基金Shenzhen Science and Technology Program(Grant No.JCYJ20230807091300001)the National Natural Science Foundation of China(Grant Nos.12374410 and 92050102)+1 种基金the National Key Research and Development Program of China(Grant Nos.2023YFA1407100 and 2020YFA0710100)the Fundamental Research Funds for the Central Universities(Grant No.20720220033).
文摘Metasurfaces and metagratings offer new platforms for electromagnetic wave control with significant responses.However,metasurfaces based on abrupt phase change and resonant structures suffer from the drawback of high loss and face challenges when applied in water waves.Therefore,the application of metasurfaces in water wave control is not ideal due to the limitations associated with high loss and other challenges.We have discovered that non-resonant metagratings exhibit promising effects in water wave control.Leveraging the similarity between bridges and metagratings,we have successfully developed a water wave metagrating model inspired by the ancient Luoyang Bridge in China.We conduct theoretical calculations and simulations on the metagrating and derive the equivalent anisotropic model of the metagrating.This model provides evidence that the metagrating has the capability to control water waves and achieve unidirectional surface water wave.The accuracy of our theory is strongly supported by the clear observation of the unidirectional propagation phenomenon during simulation and experiments conducted using a reduced version of the metagrating.It is the first time that the unidirectional propagation of water waves has been seen in water wave metagrating experiment.Above all,we realize the water wave metagrating experiment for the first time.By combining complex gratings with real bridges,we explore the physics embedded in the ancient building—Luoyang Bridge,which are of great significance for the water wave metagrating design and provide a new method for analyzing the effects of water waves on bridges.At the same time,this discovery also provides a new idea for ocean cargo transportation,ocean garbage cleaning,and the development and protection of ancient bridges.
文摘Ferrimagnetic materials exhibiting remanence can be used to achieve unidirectional electromagnetic-field propagation in the form of magnetoplasmons(MPs)in the subwavelength regime.This study investigates the MP properties and various guiding modes in a hollow cylindrical waveguide made of materials that exhibit remanence.Pattern analysis and numerical simulations are used to demonstrate that dispersion relationships and electromagnetic-field distribution are strongly affected by the operating frequency and physical dimensions of the structure.In addition,the existence of two different guiding modes is proved,namely regular and surface-wave modes.By adjusting the operating frequency and reducing the diameter of the hollow cylinder,the regular mode can be suppressed so as to only retain the surface-wave mode,which enables unidirectional MP propagation in the cylindrical waveguide.Moreover,the unidirectional surface-wave mode is robust to backscattering due to surface roughness and defects,which makes it very useful for application in field-enhancement devices.
基金supported by the National Natural Science Foundation of China (Grant No.12274131)the Innovation Program for Quantum Science and Technology (Grant No.2024ZD0300101)。
文摘Optical non-reciprocity is a fundamental phenomenon in photonics.It is crucial for developing devices that rely on directional signal control,such as optical isolators and circulators.However,most research in this field has focused on systems in equilibrium or steady states.In this work,we demonstrate a room-temperature Rydberg atomic platform where the unidirectional propagation of light acts as a switch to mediate time-crystalline-like collective oscillations through atomic synchronization.
基金financially supported by the National Natural Science Foundation of China(Nos.11774055 and 12074066)。
文摘Photonic structures with topological edge states and resonance loops are both important in optical communication systems,but they are usually two separate structures.In order to obtain a photonic system combining properties from both,we design multiple-layer nested photonic topological structures.The nested topological loops not only have topological protection immune to structural disorder and defects,but also possess both the properties of unidirectional propagation and loop resonance.Through mode analysis and simulations,we find that the transport can form diverse circulation loops.Each loop has its own resonance frequencies and can be solely excited in the nested layered structure through choosing its resonance frequencies.As a result,this work shows great application prospects in the area of reconfigurable photonic circuits.
