Beam-splitter operations are an indispensable resource for processing quantum information encoded in bosonic modes. In hybrid quantum systems, however, it can be challenging to implement reliable beam-splitters between two distinct modes due to various experimental imperfections. Without beam-splitters, realizing arbitrary Gaussian operations between bosonic modes can become highly non-trivial or even infeasible. In this work, we develop interference-based protocols for engineering Gaussian operations in multi-mode hybrid bosonic systems without requiring beam-splitters. Specifically, for a given generic multi-mode Gaussian unitary coupler, we demonstrate a universal scheme for constructing Gaussian operations on a desired subset of the modes, requiring only multiple uses of the given coupler interleaved with single-mode Gaussian unitaries. Our results provide efficient construction of operations crucial to quantum information science, and are derived from fundamental physical properties of bosonic systems. The proposed scheme is thus widely applicable to existing platforms and couplers, with the exception of certain edge cases. We introduce a systematic approach to identify and treat these edge cases by utilizing an intrinsically invariant structure associated with our interference-based construction.

分束器操作是处理以玻色子模式编码的量子信息不可或缺的资源。然而，在混合量子系统中，由于各种实验缺陷，在两种不同模式之间实现可靠的分束器可能具有挑战性。如果没有分束器，实现玻色子模式之间的任意高斯运算可能变得非常重要，甚至是不可行的。在这项工作中，我们开发了基于干扰的协议，用于在多模混合玻色子系统中设计高斯操作，而无需分束器。具体来说，对于给定的通用多模高斯酉耦合器，我们演示了一种通用方案，用于在所需的模式子集上构建高斯运算，只需要多次使用与单模高斯酉交错的给定耦合器。我们的结果提供了对量子信息科学至关重要的操作的有效构建，并且源自玻色子系统的基本物理特性。因此，提出的方案广泛适用于现有平台和耦合器，但某些边缘情况除外。我们引入了一种系统的方法来识别和处理这些边缘情况，方法是利用与我们的基于干扰的结构相关的内在不变的结构。