In this article we use time-dependent Josephson coupling to enhance unconventional photon blockade in a system of two coupled nonlinear bosonic modes which are initially loaded with weakly populated coherent states, so the evolution is restricted to the manifold of up to two field quanta. Using numerical optimal control, we find the optimal coupling which minimizes the two-photon occupation of one mode, which is actually transferred to the other, while maintains a non-zero one-photon occupation in the same mode. Moreover, we choose the continuous coupling to vanish after the transfer between the modes such that they are decoupled and one of them is left only with some one-photon population which can be observed upon its decay. We numerically find lower values of the second-order correlation function obtained at earlier times than with constant coupling, with larger one-photon populations and for longer time windows, corresponding thus to higher emission efficiency and easier detection. The presented methodology is not restricted to the system under study, but it can also be transferred to other related frameworks, to find the optimal driving fields which can improve the single-photon emission statistics from these systems.

中文翻译：

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使用最佳耦合的玻色约瑟夫森结中的动态封锁

在本文中，我们使用时间相关的约瑟夫森耦合来增强两个偶合的非线性玻色子模式系统中的非常规光子阻挡，该系统最初加载有弱填充的相干态，因此其演化仅限于两个场量子的流形。使用数值最优控制，我们找到了最优耦合，该最优耦合将一种模式的双光子占有率最小化，而该模式实际上转移到了另一种模式，而在同一模式下保持了非零的单光子占有率。此外，我们选择在模式之间转移之后消失的连续耦合，以使它们解耦，并且其中一个仅留下一些单光子种群，当其衰变时可以观察到。从数值上看，我们发现与恒定耦合相比，在较早的时间获得的二阶相关函数的值较低，具有较大的单光子数量和较长的时间窗口，因此对应于较高的发射效率和更易于检测。提出的方法不仅限于所研究的系统，还可以转移到其他相关框架中，以找到最佳的驱动场，从而改善这些系统的单光子发射统计数据。