摘要
By using Dirac–Heisenberg–Wigner formalism we study electron–positron pair production for linear, elliptic, nearly circular, and circular polarizations of electric fields with symmetrical frequency chirp, and we obtain momentum spectra and pair yield. The difference of results among polarized fields is obvious for the small chirp. When the chirp parameter increases, the momentum spectra tend to exhibit the multiphoton pair generation that is characterized by the multi-concentric ring structure. The increase of the number density is also remarkable compared to the case of asymmetrical frequency chirp. Note that the dynamically assisted Schwinger mechanism plays an important role for the enhanced pair production in the symmetrical frequency chirp.
作者
Kun Wang
Xuehua Hu
Sayipjamal Dulat
Bai-Song Xie
王焜;胡学华;Sayipjamal Dulat;谢柏松(School of Physics and Technology,Xinjiang University,Urumqi 830046,China;Key Laboratory of Beam Technology of the Ministry of Education,and College of Nuclear Science and Technology,Beijing Normal University,Beijing 100875,China;Beijing Radiation Center,Beijing 100875,China)
基金
supported by the National Natural Science Foundation of China (Grant Nos. 11875007, 11935008, and 11965020)。
