标题： 半经典理论在强场等离子体区域的适用性 显示英文标题

标题： Applicability of semi-classical theories in the strong field plasma regime

摘要： 对于许多目的来说，经典等离子体动力学模型即使在强电磁场（接近 Schwinger 临界场）和高频率（接近 Compton 频率）的情况下也能出乎意料地良好工作。 然而，经典模型的适用性往往对问题的细节非常敏感。 在本文中，我们研究了等离子体振荡的具体情况，以区分经典和量子相对论区域。 由于研究的场几何结构，像辐射反应和 Breit-Wheeler 对产生这样的机制，在电磁场中通常很重要，但在这里被有效地抑制了。 此外，我们发现与自由电流相比，电子自旋引起的极化电流在低于 Compton 频率时通常是可忽略的，自由电流的大小由经典 Vlasov 理论很好地近似。 然而，我们表明，由于 Schwinger 机制引起的对产生有时在相当适中的场强下可能很重要，大约是临界场的 10% 甚至更小。 给出了当可以应用经典 Vlasov 理论的粗略指导原则。 显示英文摘要

摘要： For many purposes, classical plasma dynamics models can work surprisingly well even for strong electromagnetic fields, approaching the Schwinger critical fields, and high frequencies, approaching the Compton frequency. However, the applicability of classical models tends to depend rather sensitively on the details of the problem. In the present paper, we study the specific case of plasma oscillations to draw a line between the classical and quantum relativistic regimes. Due to the field geometry of study, mechanisms like radiation reaction and Breit-Wheeler pair production, which tend to be important for electromagnetic fields, are rather effectively suppressed. Moreover, we find that the polarization current due to the electron spin is generally negligible for frequencies below the Compton frequency, compared to the free current, whose magnitude is well-approximated by the classical Vlasov theory. However, we show that pair creation due to the Schwinger mechanism can sometimes be important for surprisingly modest field strengths, of the order of 10 % of the critical field or even smaller. A rough guideline for when the classical Vlasov theory can be applied is given