AI 中文总结
研究利用计算量子场论，发现具有相对相位的两个电场产生正负电子对时，对产生量随相对相位呈类余弦依赖，且跃迁周期与光子阶数相关，可用于识别多光子跃迁阶数。
AI 中文摘要
我们采用计算量子场论，研究具有相对相位的两个时空非均匀电场产生正负电子对的过程。发现当两个电场间距较近时，对产生量对相对相位呈现类余弦依赖关系，表明相对相位是增强多光子跃迁通道的有效方式。进一步分析显示，对产生通道对相对相位的响应随跃迁光子阶数显著变化：单光子跃迁的速率具有2π周期性，双光子跃迁则呈现π的缩减周期性。为阐明潜在机制，我们将量子场论框架映射到含时微扰方法，通过将该方法扩展到n光子过程，证明跃迁概率对相对相位的周期为2π/n。这一发现表明，相对相位是识别多光子跃迁阶数的有效手段。
英文摘要
We investigate the creation of electron-positron pairs by two spatiotemporally inhomogeneous electric fields with a relative phase, employing computational quantum field theory. We find that, when the two fields are closely spaced, the pair yield exhibits a cosine-like dependence on the relative phase. This suggests that the relative phase provides an effective way to enhance multi-photon transition channels. Furthermore, our analysis reveals that the response of pair-creation channels to the relative phase changes substantially with the photon order of the transition. For one-photon transitions, the rate exhibits a $2π$ periodicity, whereas a reduced periodicity of $π$ is observed for two-photon transitions. To clarify the underlying mechanism, we map the quantum field-theoretical framework onto a time-dependent perturbation approach. By extending this approach to $n$-photon processes, we show that the transition probability is periodic in the relative phase with period $2π/n$. This observation suggests that the relative phase offers an effective means of identifying the order of multi-photon transitions.
