论文标题

使用本地测量来推断量子网络拓扑

Inferring Quantum Network Topology using Local Measurements

论文作者

Chen, Daniel T., Doolittle, Brian, Larson, Jeffrey M., Saleem, Zain H., Chitambar, Eric

论文摘要

可以在量子网络中跨节点生成的统计相关性取决于其拓扑。但是,此拓扑信息可能尚不清楚,或者可能需要验证。在本文中,我们提出了一个有效的协议,用于区分和推断量子网络的拓扑。我们利用熵量(即von Neumann熵和测得的共同信息)以及测量协方差来独特地表征拓扑。我们表明,熵数量足以区分两个准备GHz状态的网络。此外,如果可用量子量测量值,则可以使用熵数量和协方差来推断网络拓扑,而无需任何状态准备假设。我们表明该协议可以完全鲁棒对噪声,并且可以通过量子变化优化实现。对经典模拟器和量子硬件的数值实验表明,协方差通常更可靠,可以准确有效地推断拓扑,而基于熵的方法通常可以更好地确定低射击状态中没有纠缠的方法。

Statistical correlations that can be generated across the nodes in a quantum network depend crucially on its topology. However, this topological information might not be known a priori, or it may need to be verified. In this paper, we propose an efficient protocol for distinguishing and inferring the topology of a quantum network. We leverage entropic quantities -- namely, the von Neumann entropy and the measured mutual information -- as well as measurement covariance to uniquely characterize the topology. We show that the entropic quantities are sufficient to distinguish two networks that prepare GHZ states. Moreover, if qubit measurements are available, both entropic quantities and covariance can be used to infer the network topology without state-preparation assumptions. We show that the protocol can be entirely robust to noise and can be implemented via quantum variational optimization. Numerical experiments on both classical simulators and quantum hardware show that covariance is generally more reliable for accurately and efficiently inferring the topology, whereas entropy-based methods are often better at identifying the absence of entanglement in the low-shot regime.

扫码加入交流群

加入微信交流群

微信交流群二维码

扫码加入学术交流群,获取更多资源