In this paper,we theoretically investigate the existence and propagation of low amplitude nonlinear ion waves in a dense plasma under the influence of a strong magnetic field.The plasma consists of ultra-relativistic ...In this paper,we theoretically investigate the existence and propagation of low amplitude nonlinear ion waves in a dense plasma under the influence of a strong magnetic field.The plasma consists of ultra-relativistic and degenerate electrons and positrons and non-degenerate cold ions.Firstly,the appearance of two distinct linear modes and their evolution is studied by deriving a dispersion equation with the aid of Fourier analysis.Secondly,the dynamics of low amplitude ion solitary structures is investigated via a Korteweg-de Vries equation derived by employing a reductive perturbation method.The effects of various plasma parameters like positron concentration,strength of magnetic field,obliqueness of field,etc.,are discussed in detail.At the end,analytical results are supplemented through numerical analysis by using typical representative parameters consistent with degenerate and ultra-relativistic magnetoplasmas of astrophysical regimes.展开更多
The far-zone scattered spectral density of a light wave on the scattering from a collection of particles is investigated, and the relationship between the character of the collection and the distribution of the scatte...The far-zone scattered spectral density of a light wave on the scattering from a collection of particles is investigated, and the relationship between the character of the collection and the distribution of the scattered spectral density is discussed. It is shown that both the number of particles and their locations in the collection play roles in the distribution of the far-zone scattered spectral density. This phenomenon may provide a potential method to reconstruct the structure character of a collection of particles from measurements of the far-zone scattered spectral density.展开更多
We report the Hong–Ou–Mandel（HOM） interference, with visibility of 91%, produced from two independent single photons retrieved from collective atomic excitations in two separate cold-atom clouds with high optical ...We report the Hong–Ou–Mandel（HOM） interference, with visibility of 91%, produced from two independent single photons retrieved from collective atomic excitations in two separate cold-atom clouds with high optical depths of 90. The high visibility of the HOM dip is ascribed to the pure single photon in the Fock state that was generated from a dense-cold-atom cloud pumping by a short pulse. The visibility is always the same regardless of the time response of the single-photon detectors. This result experimentally shows that the single photons retrieved are in a separable temporal state with their idler photons.展开更多
文摘In this paper,we theoretically investigate the existence and propagation of low amplitude nonlinear ion waves in a dense plasma under the influence of a strong magnetic field.The plasma consists of ultra-relativistic and degenerate electrons and positrons and non-degenerate cold ions.Firstly,the appearance of two distinct linear modes and their evolution is studied by deriving a dispersion equation with the aid of Fourier analysis.Secondly,the dynamics of low amplitude ion solitary structures is investigated via a Korteweg-de Vries equation derived by employing a reductive perturbation method.The effects of various plasma parameters like positron concentration,strength of magnetic field,obliqueness of field,etc.,are discussed in detail.At the end,analytical results are supplemented through numerical analysis by using typical representative parameters consistent with degenerate and ultra-relativistic magnetoplasmas of astrophysical regimes.
基金supported by the National Natural Science Foundation of China (Nos. 11404231, 61475105, and 11474253)the Construction Plan for Scientific Research Innovation Teams of Universities in Sichuan Province (No. 12TD008)
文摘The far-zone scattered spectral density of a light wave on the scattering from a collection of particles is investigated, and the relationship between the character of the collection and the distribution of the scattered spectral density is discussed. It is shown that both the number of particles and their locations in the collection play roles in the distribution of the far-zone scattered spectral density. This phenomenon may provide a potential method to reconstruct the structure character of a collection of particles from measurements of the far-zone scattered spectral density.
基金supported by National 973 Program of China(No.2011CB921604)the National Natural Science Foundation of China(NSFC)through the major research plan(Precision Measurement Physics Grant No.91436211)+1 种基金the NSFC Key Research Program(No.11234003)the Young Scientists Research Program(No.11204086)
文摘We report the Hong–Ou–Mandel（HOM） interference, with visibility of 91%, produced from two independent single photons retrieved from collective atomic excitations in two separate cold-atom clouds with high optical depths of 90. The high visibility of the HOM dip is ascribed to the pure single photon in the Fock state that was generated from a dense-cold-atom cloud pumping by a short pulse. The visibility is always the same regardless of the time response of the single-photon detectors. This result experimentally shows that the single photons retrieved are in a separable temporal state with their idler photons.
