In recent years,materials with asymmetric mechanical response properties(mechanical Janus materials)have been found possess numerous potential applications,i.e.shock absorption and vibration isolation.In this study,we...In recent years,materials with asymmetric mechanical response properties(mechanical Janus materials)have been found possess numerous potential applications,i.e.shock absorption and vibration isolation.In this study,we propose a novel mechanical Janus lattice whose asymmetric mechanical response can be switched in orientation by a plug.Through finite element analysis and experimental verification,this lattice exhibits asymmetric displacement responses to symmetric forces.Furthermore,with such a plug structure inside,individual lattices can switch the orientation of asymmetry and thus achieve reprogrammable design of a mechanical structure with chained lattices.The reprogrammable asymmetry of this material will offer multiple functions in design of mechanical metamaterials.展开更多
We experimentally demonstrate an ultra-thin plasmonic optical rotator in the visible regime that induces a polarization rotation that is continuously tunable and switchable by an external magnetic field.The rotator is...We experimentally demonstrate an ultra-thin plasmonic optical rotator in the visible regime that induces a polarization rotation that is continuously tunable and switchable by an external magnetic field.The rotator is a magneto-plasmonic hybrid structure consisting of a magneto-optical EuSe slab and a one-dimensional plasmonic gold grating.At low temperatures,EuSe possesses a large Verdet constant and exhibits Faraday rotation,which does not saturate over a regime of several Tesla.By combining these properties with plasmonic Faraday rotation enhancement,a large tuning range of the polarization rotation of up to 8.4° for a film thickness of 220 nm is achieved.Furthermore,through experiments and simulations,we demonstrate that the unique dispersion properties of the structure enable us to tailor the wavelengths of the tunable polarization rotation to arbitrary spectral positions within the transparency window of the magneto-optical slab.The demonstrated concept might lead to important,highly integrated,non-reciprocal,photonic devices for light modulation,optical isolation,and magnetic field optical sensing.The simple fabrication of EuSe nanostructures by physical vapor deposition opens the way for many potentially interesting magneto-plasmonic systems and three-dimensional magneto-optical metamaterials.展开更多
Non-reciprocal sound transmission is demonstrated in an electro-acoustic system consisting of two shunt loudspeakers with time-modulated circuits.The shunt circuit is modulated by periodically varying the resistance i...Non-reciprocal sound transmission is demonstrated in an electro-acoustic system consisting of two shunt loudspeakers with time-modulated circuits.The shunt circuit is modulated by periodically varying the resistance in time sequence,and a phase difference of time modulation is set between two sets of loudspeakers to produce a spatial bias.The spatiotemporal modulation of acoustic properties is thus formed to break the reciprocity.The theoretical model based on the transfer-matrix method is developed to predict acoustic scatterings of electro-acoustic systems.Acoustic asymmetric transmission in opposite directions is disclosed by the model and is verified by time-domain simulation results based on the finite-difference time-domain method.Asymmetric transmission in multiple frequency bands can be created by tuning circuit parameters,showing their ability in regulating acoustic non-reciprocal behavior.This study may provide a platform for the design of compact and non-reciprocal acoustic devices with applications to efficient noise control.展开更多
Electromagnetically induced transparency has the unique ability to optically control transparency windows with low light in atomic systems.However,its practical applications in quantum physics and information science ...Electromagnetically induced transparency has the unique ability to optically control transparency windows with low light in atomic systems.However,its practical applications in quantum physics and information science are limited due to rigid experimental requirements.Here we demonstrate a new mechanism of optically induced transparency in a micro-cavity by introducing a four-wave mixing gain to nonlinearly couple two separated resonances of the micro-cavity in an ambient environment.A signature Fano-like resonance was observed owing to the nonlinear interference of the two coupled resonances.Moreover,we show that the unidirectional gain of the four-wave mixing can lead to the remarkable effect of non-reciprocal transmission at the transparency windows.Optically induced transparency may offer a unique platform for a compact,integrated solution to all-optical and quantum information.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.52075411 and U1913213)Shaanxi Key Research and Development Program(Grant No.2020ZDLGY06-11).
文摘In recent years,materials with asymmetric mechanical response properties(mechanical Janus materials)have been found possess numerous potential applications,i.e.shock absorption and vibration isolation.In this study,we propose a novel mechanical Janus lattice whose asymmetric mechanical response can be switched in orientation by a plug.Through finite element analysis and experimental verification,this lattice exhibits asymmetric displacement responses to symmetric forces.Furthermore,with such a plug structure inside,individual lattices can switch the orientation of asymmetry and thus achieve reprogrammable design of a mechanical structure with chained lattices.The reprogrammable asymmetry of this material will offer multiple functions in design of mechanical metamaterials.
基金We gratefully acknowledge the funding by DFG(SPP1391,FOR730,and GI 269/11-1),BMBF(FARADAY,FKZ 13N12443)MWK,Baden-Wurttemberg Stiftung and ERC(ComplexPlas)JYC and DD also acknowledge support from Carl-Zeiss-Stiftung.
文摘We experimentally demonstrate an ultra-thin plasmonic optical rotator in the visible regime that induces a polarization rotation that is continuously tunable and switchable by an external magnetic field.The rotator is a magneto-plasmonic hybrid structure consisting of a magneto-optical EuSe slab and a one-dimensional plasmonic gold grating.At low temperatures,EuSe possesses a large Verdet constant and exhibits Faraday rotation,which does not saturate over a regime of several Tesla.By combining these properties with plasmonic Faraday rotation enhancement,a large tuning range of the polarization rotation of up to 8.4° for a film thickness of 220 nm is achieved.Furthermore,through experiments and simulations,we demonstrate that the unique dispersion properties of the structure enable us to tailor the wavelengths of the tunable polarization rotation to arbitrary spectral positions within the transparency window of the magneto-optical slab.The demonstrated concept might lead to important,highly integrated,non-reciprocal,photonic devices for light modulation,optical isolation,and magnetic field optical sensing.The simple fabrication of EuSe nanostructures by physical vapor deposition opens the way for many potentially interesting magneto-plasmonic systems and three-dimensional magneto-optical metamaterials.
基金supported by the National Natural Science Foundation of China (Grant Nos.11872111,11991030,11991033,and 11622215)the 111 Project (Grant No.B16003).
文摘Non-reciprocal sound transmission is demonstrated in an electro-acoustic system consisting of two shunt loudspeakers with time-modulated circuits.The shunt circuit is modulated by periodically varying the resistance in time sequence,and a phase difference of time modulation is set between two sets of loudspeakers to produce a spatial bias.The spatiotemporal modulation of acoustic properties is thus formed to break the reciprocity.The theoretical model based on the transfer-matrix method is developed to predict acoustic scatterings of electro-acoustic systems.Acoustic asymmetric transmission in opposite directions is disclosed by the model and is verified by time-domain simulation results based on the finite-difference time-domain method.Asymmetric transmission in multiple frequency bands can be created by tuning circuit parameters,showing their ability in regulating acoustic non-reciprocal behavior.This study may provide a platform for the design of compact and non-reciprocal acoustic devices with applications to efficient noise control.
基金supported by the National Natural Science Foundation of China(grant nos 11304201 and 61475100)the National 1000-plan Program(Youth),the Shanghai Pujiang Talent Program(grant no.12PJ1404700)the Shanghai Scientific Innovation Program(grant no.14JC1402900).
文摘Electromagnetically induced transparency has the unique ability to optically control transparency windows with low light in atomic systems.However,its practical applications in quantum physics and information science are limited due to rigid experimental requirements.Here we demonstrate a new mechanism of optically induced transparency in a micro-cavity by introducing a four-wave mixing gain to nonlinearly couple two separated resonances of the micro-cavity in an ambient environment.A signature Fano-like resonance was observed owing to the nonlinear interference of the two coupled resonances.Moreover,we show that the unidirectional gain of the four-wave mixing can lead to the remarkable effect of non-reciprocal transmission at the transparency windows.Optically induced transparency may offer a unique platform for a compact,integrated solution to all-optical and quantum information.
