Electron-positron pair production in spatial inhomogeneous electric fields with sinusoidal phase modulation is studied within the Dirac-Heisenberg-Wigner formalism.The focus is on discussing the effects of the modulat...Electron-positron pair production in spatial inhomogeneous electric fields with sinusoidal phase modulation is studied within the Dirac-Heisenberg-Wigner formalism.The focus is on discussing the effects of the modulation parameters on the momentum spectrum and the reduced particle number at various spatial scales.For the momentum spectrum,the interference effect becomes more and more remarkable with the increase of modulated amplitude or frequency,while the symmetry is severely destroyed with modulated amplitude.For the reduced particle number,it is greatly enhanced by about a few times and evenly one order of magnitude when modulation parameters are applied.Moreover,the effect of spatial scales on the reduced particle number is carefully examined,and it is found that it increases rapidly at small spatial scales,while it tends to be a constant at large spatial scales.We also obtain the optimal pair production that can be achieved through different modulations.These results can provide a possibility for realizing the optimal pair production by combining the advantages of field spatial inhomogeneity with different choices of phase modulation.展开更多
The target characteristic polarization state in the co-polarized channel for the coherent case was studied in greater detail, with emphasis on the analysis of the characteristic polarization states variable with the t...The target characteristic polarization state in the co-polarized channel for the coherent case was studied in greater detail, with emphasis on the analysis of the characteristic polarization states variable with the target parameters. The Sinclair backscatter matrix was diagonalized under the change of polariza- tion basis via a unitary transformation matrix. Then the diagonal matrix was parameterized by four parameters viz. matrix amplitude, absolute phase, amplitude ratio and phase difference. The behavior of the characteristic polarization states with the varieties of target parameters was discussed together with the power density plot. The characteristic polarization states were displayed on the Poincare sphere and six conclusions were obtained, which provide theoretic support for decreasing the computational complexity of target characteristic polarization state, or anticipating its position in the power density plot. Several simple target cases were considered for validating these conclusions.展开更多
In this paper, the solution of Chebyshev equation with its argument being greater than 1 is obtained. The initial value of the derivative of the solution is the expression of magnetization, which is valid for any spin...In this paper, the solution of Chebyshev equation with its argument being greater than 1 is obtained. The initial value of the derivative of the solution is the expression of magnetization, which is valid for any spin quantum number S. The Chebyshev equation is transformed from an ordinary differential equation obtained when we dealt with Heisenberg model, in order to calculate all three components of magnetization, by many-body Green＇s function under random phase approximation. The Chebyshev functions with argument being greater than 1 are discussed. This paper shows that the Chebyshev polynomials with their argument being greater than 1 have their physical application.展开更多
基金the National Natural Science Foundation of China(NSFC)under Grant No.11875007 and No.11935008
文摘Electron-positron pair production in spatial inhomogeneous electric fields with sinusoidal phase modulation is studied within the Dirac-Heisenberg-Wigner formalism.The focus is on discussing the effects of the modulation parameters on the momentum spectrum and the reduced particle number at various spatial scales.For the momentum spectrum,the interference effect becomes more and more remarkable with the increase of modulated amplitude or frequency,while the symmetry is severely destroyed with modulated amplitude.For the reduced particle number,it is greatly enhanced by about a few times and evenly one order of magnitude when modulation parameters are applied.Moreover,the effect of spatial scales on the reduced particle number is carefully examined,and it is found that it increases rapidly at small spatial scales,while it tends to be a constant at large spatial scales.We also obtain the optimal pair production that can be achieved through different modulations.These results can provide a possibility for realizing the optimal pair production by combining the advantages of field spatial inhomogeneity with different choices of phase modulation.
基金Supported by Department of Electronic Science and Engineering, National University of Defense Technology, China
文摘The target characteristic polarization state in the co-polarized channel for the coherent case was studied in greater detail, with emphasis on the analysis of the characteristic polarization states variable with the target parameters. The Sinclair backscatter matrix was diagonalized under the change of polariza- tion basis via a unitary transformation matrix. Then the diagonal matrix was parameterized by four parameters viz. matrix amplitude, absolute phase, amplitude ratio and phase difference. The behavior of the characteristic polarization states with the varieties of target parameters was discussed together with the power density plot. The characteristic polarization states were displayed on the Poincare sphere and six conclusions were obtained, which provide theoretic support for decreasing the computational complexity of target characteristic polarization state, or anticipating its position in the power density plot. Several simple target cases were considered for validating these conclusions.
基金The project supported by the State Key Project of Fundamental Research of China under Grant No. G2000067101
文摘In this paper, the solution of Chebyshev equation with its argument being greater than 1 is obtained. The initial value of the derivative of the solution is the expression of magnetization, which is valid for any spin quantum number S. The Chebyshev equation is transformed from an ordinary differential equation obtained when we dealt with Heisenberg model, in order to calculate all three components of magnetization, by many-body Green＇s function under random phase approximation. The Chebyshev functions with argument being greater than 1 are discussed. This paper shows that the Chebyshev polynomials with their argument being greater than 1 have their physical application.
