标题： 树级QED过程中的完备互补关系 显示英文标题

标题： Complete complementarity relations in tree level QED processes

摘要： 我们利用完全互补关系（CCR）来全面表征QED树级散射过程中量子性的各个方面。 作为一个范例，我们考虑了Bhabha散射的两种不同配置：在第一种情况下，初始态在自旋上是可分离的，我们研究了由于散射而产生的纠缠生成。 然后我们考虑了最一般的情况，即初始态可以是纠缠态：我们发现散射以一种非平凡的方式在粒子的自旋自由度之间产生和分配量子信息，并且保留了CCR关系。 我们分析的一个重要结果是，在仅涉及费米子作为输入和输出状态的散射过程中，最大纠缠态被守恒；如果存在光子，则情况更为复杂。 显示英文摘要

摘要： We exploit the complete complementarity relations (CCR) to fully characterize various aspects of quantumness in QED scattering processes at tree level. As a paradigmatic example, we consider Bhabha scattering in two different configurations: in the first case, the initial state is factorized in the spin and we study the generation of entanglement due to the scattering. Then we consider the most general case in which the initial state can be entangled: we find that the scattering generates and distributes quantum information in a non-trivial way among the spin degrees of freedom of the particles, with CCR relations being preserved. An important outcome of our analysis is that maximal entanglement is conserved in the scattering process involving only fermions as input and output states, with a more complex situation if photons are present.