Data and code underlying the publication "Quantum-network nodes with real-time noise mitigation using spectator qubits"

Data and jupyter notebooks to reproduce the figures contained in the manuscript called "Quantum-network nodes with real-time noise mitigation using spectator qubits". The objective of the manuscript is to demonstrate improved quantum state storage using ancillary spectator qubits. Measurements on these spectator qubits reveal information about the (correlated) noise that has acted on the memory qubit, that can then be (partially) corrected in real time. The dataset contains simulations and measurements on using spectator qubits in the context of generating entanglement between distant NV centers in diamond. Surrounding nuclear spins act as memory qubit and spectator qubits. We demonstrate both a measurement-based implementation of the spectator qubit protocol and identify that measurements impart additional dephasing. We bypass these measurements in a gate-based implementation. Based on our measurements we show the spectator-induced improvements in memory fidelity for different entanglement generation success probabilities.

本数据集包含复现题为《使用旁观者量子比特（spectator qubits）实现实时噪声抑制的量子网络节点》的学术论文中所有图表所需的数据与Jupyter笔记本代码。本论文的研究目标是借助辅助旁观者量子比特，实现性能更优的量子态存储：对这些旁观者量子比特进行测量，可以获取作用于存储量子比特的（关联）噪声信息，进而实现实时的（部分）噪声校正。本数据集涵盖在金刚石中远距离氮-空位（NV, nitrogen-vacancy）中心之间生成纠缠态的场景下，使用旁观者量子比特开展的相关仿真与实验测量数据。周围的核自旋可作为存储量子比特与旁观者量子比特。本研究既实现了基于测量的旁观者量子比特协议方案，同时发现测量过程会引入额外的退相效应；我们在基于量子门的实现方案中规避了这类测量操作。基于实验测量结果，我们证明了在不同纠缠态生成成功概率下，旁观者量子比特方案可有效提升存储保真度。