标题： 关于参数下转换在生成高阶Fock态中的可扩展性 显示英文标题

标题： On the scalability of parametric down-conversion for generating higher-order Fock states

摘要： 自发参量下转换（SPDC）是生成高阶福克态（$n\geq 2$）最常用的方法。 然而，从基本原理出发的一致性能分析尚缺。 在此，我们通过引入一个考虑损耗和多模发射的状态保真度和生成概率框架来解决这个问题。 通过这种分析，我们展示了该过程的基本限制以及状态保真度和生成速率之间的权衡，这源于该过程的概率本质。 这确定了在生成用于量子应用的高阶福克态时SPDC有用参数空间。 我们实验研究了SPDC的强泵浦区域，并展示了至多$\lvert n\rangle =4$的后选择福克态。 显示英文摘要

摘要： Spontaneous parametric down-conversion (SPDC) is the most widely-used method to generate higher-order Fock states ($n\geq 2$). Yet, a consistent performance analysis from fundamental principles is missing. Here we address this problem by introducing a framework for state fidelity and generation probability under the consideration of losses and multimode emission. With this analysis we show the fundamental limitations of this process as well as a trade-off between state fidelity and generation rate intrinsic to the probabilistic nature of the process. This identifies the parameter space for which SPDC is useful when generating higher-order Fock states for quantum applications. We experimentally investigate the strong pump regime of SPDC and demonstrate heralded Fock states up to $\lvert n\rangle =4$.