We design a multilayer cylindrical structure to realize superscattering of underwater sound. Because of the near degeneracy of resonances in multiple channels of the structure, the scattering contributions from these ...We design a multilayer cylindrical structure to realize superscattering of underwater sound. Because of the near degeneracy of resonances in multiple channels of the structure, the scattering contributions from these resonances can overlap to break the single-channel limit of subwavelength objects. However, tuning the design parameters to achieve the target response is an optimization process that is tedious and time-consuming. Here,we demonstrate that a well-trained tandem neural network can deal with this problem efficiently, which can not only forwardly predict the scattering spectra of the multilayer structure with high precision, but also inversely design the required structural parameters efficiently.展开更多
We propose an alternative scheme to prepare W state by using superconducting quantum-interference devices （SQUIDs） coupled to a largely-detuned cavity. The present scheme is based on evolution by adiabatic passage, ...We propose an alternative scheme to prepare W state by using superconducting quantum-interference devices （SQUIDs） coupled to a largely-detuned cavity. The present scheme is based on evolution by adiabatic passage, where only by tuning adiabatically the Rabi frequencies of the classical microwave pulses we can obtain the standard W state without measurement or any auxiliary SQUIDs. Thus the procedure is simplified and the scheme can be achieved with very high success probability since the errors in dynamical or geometric ways can be avoided. In addition, the SQUID system and the cavity have no probability of being excited state. Thus decoherence caused by the excited-level spontaneous emission or the cavity decay is suppressed.展开更多
This paper derives the force of the electromagnetic radiation on left-handed materials （LHMs） by a direct application of the Lorentz law of classical electrodynamics. The expressions of radiation force are given for...This paper derives the force of the electromagnetic radiation on left-handed materials （LHMs） by a direct application of the Lorentz law of classical electrodynamics. The expressions of radiation force are given for TE-polarised and TM-polarised fields. The numerical results demonstrate that electromagnetic waves exert an inverse lateral radiation force on each edge of the beams, that is, the lateral pressure is expansive for TE-polarised beams and compressive for TM-polarised beams. The investigation of the radiation force will provide insights into the fundamental properties of LHMs and will provide to better understanding of the interaction of light with LHMs.展开更多
We design and analyze a novel multiband left-handed metamaterial based on a fishnet-like structure at terahertz （THz） frequencies.The metamaterial exhibits simultaneous negative refractions around the frequencies of...We design and analyze a novel multiband left-handed metamaterial based on a fishnet-like structure at terahertz （THz） frequencies.The metamaterial exhibits simultaneous negative refractions around the frequencies of 0.48,1.05,and 1.19 THz for the electromagnetic （EM） wave normal incidence,and around the frequencies of 0.20,0.79,and 1.13 THz for parallel incidence.The simulated results verify the left-handed properties.A particularly important observation is the capability of the proposed metamaterial with a single geometrical structure to display multifrequency operations in a unit cell.The compact metamaterial is a major step toward the miniaturization of THz materials and devices suitable for multifrequencies.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.12174353,41974059,and 41830537)。
文摘We design a multilayer cylindrical structure to realize superscattering of underwater sound. Because of the near degeneracy of resonances in multiple channels of the structure, the scattering contributions from these resonances can overlap to break the single-channel limit of subwavelength objects. However, tuning the design parameters to achieve the target response is an optimization process that is tedious and time-consuming. Here,we demonstrate that a well-trained tandem neural network can deal with this problem efficiently, which can not only forwardly predict the scattering spectra of the multilayer structure with high precision, but also inversely design the required structural parameters efficiently.
文摘We propose an alternative scheme to prepare W state by using superconducting quantum-interference devices （SQUIDs） coupled to a largely-detuned cavity. The present scheme is based on evolution by adiabatic passage, where only by tuning adiabatically the Rabi frequencies of the classical microwave pulses we can obtain the standard W state without measurement or any auxiliary SQUIDs. Thus the procedure is simplified and the scheme can be achieved with very high success probability since the errors in dynamical or geometric ways can be avoided. In addition, the SQUID system and the cavity have no probability of being excited state. Thus decoherence caused by the excited-level spontaneous emission or the cavity decay is suppressed.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10974063)the Research Foundation of Wuhan National Laboratory (Grant No. P080008)the National "973" Project (Grant No. 2007CB310403)
文摘This paper derives the force of the electromagnetic radiation on left-handed materials （LHMs） by a direct application of the Lorentz law of classical electrodynamics. The expressions of radiation force are given for TE-polarised and TM-polarised fields. The numerical results demonstrate that electromagnetic waves exert an inverse lateral radiation force on each edge of the beams, that is, the lateral pressure is expansive for TE-polarised beams and compressive for TM-polarised beams. The investigation of the radiation force will provide insights into the fundamental properties of LHMs and will provide to better understanding of the interaction of light with LHMs.
基金supported by the National Natural Science Foundation of China (Nos. 10974063 and 10876010)the Foundation Research Funds for the Central Universities (No. 2010MS041)
文摘We design and analyze a novel multiband left-handed metamaterial based on a fishnet-like structure at terahertz （THz） frequencies.The metamaterial exhibits simultaneous negative refractions around the frequencies of 0.48,1.05,and 1.19 THz for the electromagnetic （EM） wave normal incidence,and around the frequencies of 0.20,0.79,and 1.13 THz for parallel incidence.The simulated results verify the left-handed properties.A particularly important observation is the capability of the proposed metamaterial with a single geometrical structure to display multifrequency operations in a unit cell.The compact metamaterial is a major step toward the miniaturization of THz materials and devices suitable for multifrequencies.
