Vacuum polarization and magnetization effects in ultra-intense laser pulse-pair plasmas

Abstract

The nonlinear effects associated with the vacuum polarization and magnetization in the propagation of ultra-intense linearly polarized laser pulse in electron-positron plasmas are investigated. Using the slowly varying envelope approximation, a modified nonlinear Schrödinger equation describing the evolution of the pulse envelope is derived based on the Maxwell equations which include the vacuum polarization and magnetization effects. The analytical and numerical analysis show that the number density of electron-positron plasmas can enhance the vacuum polarization and magnetization effects, and due to the vacuum polarization and magnetization nonlinearity, a one-dimensional laser pulse envelope soliton can be formed. The evolution of an initially Gaussian laser pulse is also discussed by numerical analysis.

Quantum electrodynamic effects on the two-stream instability

“…Also, Eqs. (7,16) allow to generalize the present results to the kinetic case, since the kinetic dispersion equation can be obtained from Eq. ( 16) by replacing the sum over the beams on the right-hand-side by an integral in velocity space [17].…”

Modulational instability of an ultra-intense laser pulse in electron–positron plasmas

“…1(d). The reason is that the nonlinearity associated with the VPM effects can dominate the nonlinearity associated with the relativistic effect and the ponderomotive force if the pulse intensity is high enough (Hu et al 2012). Figure 2 shows the variation of the maximum growth rate with respect to laser intensity and the e-p plasma number density n 0 = 10 19 cm −3 is assumed.…”

“…where the Coulomb gauge ∇ • a = 0 is used. In the linearly polarized electromagnetic wave, the radiation reaction effects are negligible (Hu et al 2012), and the electron and positron velocities approximate v p = −ca/γ p andv e = ca/γ e , where γ p,e = 1 + |a| 2 ≡ γ is the Lorentz factor and v p,e is the velocity. The subscript e(p) stands for the electrons (positrons).…”

“…Therefore, (Hu et al 2012), the generation of harmonic EM waves is neglected. For a broad beam, assuming that the laser pulse propagates along the z-axis direction, and introducing an axial coordinate in a frame moving together with the laser pulse,τ = t,ζ = z − v g t, where v g = (c 2 /ω 0 )k is the group velocity of the laser pulse, the wave equation can be obtained from (9), (10) and (15) (Hu et al 2012…”

Quantum electrodynamic effects on the two-stream instability

“…The rise of extreme plasma physics [1][2][3], where fields are so intense that quantum electrodynamic (QED) effects start to play a role, suggests we should revisit some basic processes in plasma physics accounting for these effects [4][5][6][7][8].…”