论文标题
Sagnac配置中量子开关的演示
Demonstration of a quantum SWITCH in a Sagnac configuration
论文作者
论文摘要
量子开关是具有不确定因果结构的过程的一个示例，并引起了其在量子电路模型中胜过因果的能力的能力。迄今为止，量子开关的实现依赖于光学干涉仪容易受到微小路径长度波动的影响，使其设计复杂化，限制了其性能，并构成了将量子开关扩展到多方的障碍。在这封信中，我们通过使用新颖的相互和通用$ \ mathrm {su}（2）$极化小工具来促进的常用path几何形状来克服这些局限性。我们通过成功执行频道歧视任务，并以几乎统一的成功概率来证明我们的设计。
The quantum SWITCH is an example of a process with an indefinite causal structure, and has attracted attention for its ability to outperform causally ordered computations within the quantum circuit model. To date, realisations of the quantum SWITCH have relied on optical interferometers susceptible to minute path length fluctuations, complicating their design, limiting their performance and posing an obstacle to extending the quantum SWITCH to multiple parties. In this Letter we overcome these limitations by demonstrating an intrinsically stable quantum SWITCH utilizing a common-path geometry facilitated by a novel reciprocal and universal $\mathrm{SU}(2)$ polarization gadget. We certify our design by successfully performing a channel discrimination task with near unity success probability.
