Electron-positron pair production in spatially inhomogeneous electric fields with quadratically symmetric chirp

Abstract

Electron-positron pair production from vacuum in spatially inhomogeneous electric fields with quadratically symmetric chirp is studied within the real-time Dirac-Heisenberg-Wigner formalism. The reduced momentum spectrum and the reduced total number of the created particles under the quadratically symmetric chirped electric field are investigated in high- and low-frequency fields. Compared with that of the quadratically asymmetric chirped field in particular, it is found that the momentum spectrum under the quadratically symmetric chirped field exhibits the stronger oscillations and the higher peaks in both high- and low- frequency fields, and it shows an obvious widening only in the high-frequency field. It is also found that the total number of the created particles of the quadratically symmetric chirped field increases with the chirp, and it is nearly twice that of the quadratically asymmetric chirped field.

Figures (8)

• Figure 1: Reduced momentum spectrum with different quadratically symmetric chirp for various spatial scales in the high-frequency field: (a), (b), and (c) represent the cases where $\lambda=300\ \mathrm{m}^{-1}$, $\lambda=10\ \mathrm{m}^{-1}$, and $\lambda=2\ \mathrm{m}^{-1}$, respectively. The insets show the magnified momentum spectrum for the chirp parameters $b_{1}=b_{2}=0$, $b_{1}=0.1\omega/2\tau$ and $b_{2}=0.1\omega/2\tau^{2}$ for clarity. The field parameters are $\epsilon=0.5$, $\omega=0.7\ \mathrm{m}$, $\tau=45\ \mathrm{m}^{-1}$, and $\phi=\pi/2$.
• Figure 2: Comparison of the reduced momentum spectrum with quadratically symmetric and quadratically asymmetric chirp in the high-frequency field. From left to right, the columns (a)--(c), (d)--(f), and (g)--(i) represent the cases of $\lambda=300\ \mathrm{m}^{-1}$, $\lambda=10\ \mathrm{m}^{-1}$, and $\lambda=2\ \mathrm{m}^{-1}$, respectively. The field parameters are the same as in Fig. \ref{['fig:1']}.
• Figure 3: The variation of the total number of created particles with the spatial scales for different high-frequency quadratically symmetric and quadratically asymmetric chirped fields, (a) and (b) represent the cases of the quadratically symmetric chirp (solid line) and quadratically asymmetric chirp (dot-dashed line), respectively. The field parameters are the same as in Fig. \ref{['fig:1']}.
• Figure 4: Reduced momentum spectrum with different quadratically symmetric chirp for various spatial scales in the low-frequency field: (a), (b), and (c) represent the cases where $\lambda=300\ \mathrm{m}^{-1}$, $\lambda=10\ \mathrm{m}^{-1}$, and $\lambda=2\ \mathrm{m}^{-1}$, respectively. The field parameters are $\epsilon=0.5$, $\omega=0.1\ \mathrm{m}$, $\tau=25\ \mathrm{m}^{-1}$, and $\phi=\pi/2$.
• Figure 5: The temporal variation of the electric field for different quadratically symmetric and quadratically asymmetric chirped fields, (a)--(d) represent the cases of $b_{1}=b_{2}=0$, $b_{1}=0.1\omega/2\tau$ and $b_{2}=0.1\omega/2\tau^{2}$, $b_{1}=0.5\omega/2\tau$ and $b_{2}=0.5\omega/2\tau^{2}$, and $b_{1}=0.9\omega/2\tau$ and $b_{2}=0.9\omega/2\tau^{2}$, respectively. The field parameters are the same as in Fig. \ref{['fig:4']}.