Several emerging quantum technologies, including quantum networks, and modular and fusion-based quantum computing, rely crucially on the ability to perform photonic Bell state measurements. Therefore, photon losses and the 50% success probablity upper bound of Bell state measurements pose a critical limitation to photonic quantum technologies. Here, we develop protocols that overcome these two key challenges through logical encoding of photonic qubits. Our approach uses a tree graph state logical encoding, which can be produced deterministically with a few quantum emitters, and achieves near-deterministic logical photonic Bell state measurements while also protecting against errors including photon losses, with a record loss-tolerance threshold.

中文翻译：

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使用实用的逻辑光子编码纠错纠缠交换

几种新兴的量子技术，包括量子网络，以及基于模块化和融合的量子计算，关键依赖于执行光子贝尔态测量的能力。因此，光子损失和贝尔态测量的 50% 成功概率上限对光子量子技术构成了关键限制。在这里，我们开发了通过光子量子位的逻辑编码来克服这两个关键挑战的协议。我们的方法使用树图状态逻辑编码，它可以用几个量子发射器确定性地产生，并实现接近确定性的逻辑光子贝尔状态测量，同时还可以防止包括光子损失在内的错误，并具有创纪录的损失容限阈值。