论文标题
使用基于能量选择性隧道的汉密尔顿估计，接近单线量子Qubit操作中的理想可见性
Approaching ideal visibility in singlet-triplet qubit operations using energy-selective tunneling-based Hamiltonian estimation
论文作者
论文摘要
我们报告了基于GAAS量子点阵列中两电子旋转值的基于能量选择性的隧道读数读数。读数保真度的优化能够平均实现16个单次测量时间，并基于实时贝叶斯推断，自适应初始化和有效的量子频率估计。对于以频率征兆模式运行的量子操作，我们观察到连贯时间增加了40倍，而无需诉诸动态核极化。我们还以量子振荡的可见性，单发测量保真度和状态初始化保真度，分别为97.7％，99％和99.7％以上。通过将基于能量选择性隧道的旋转的灵敏度推向极限，该技术对于高级量子控制方案（例如误差缓解方案）有用，其中快速Qubit参数校准具有较大的信号噪声比率至关重要。
We report energy selective tunneling readout-based Hamiltonian parameter estimation of a two-electron spin qubit in a GaAs quantum dot array. Optimization of readout fidelity enables a single-shot measurement time of 16 on average, with adaptive initialization and efficient qubit frequency estimation based on real-time Bayesian inference. For qubit operation in a frequency heralded mode, we observe a 40-fold increase in coherence time without resorting to dynamic nuclear polarization. We also demonstrate active frequency feedback with quantum oscillation visibility, single-shot measurement fidelity, and state initialization fidelity up to 97.7%, 99%, and over 99.7%, respectively. By pushing the sensitivity of the energy selective tunneling-based spin to charge conversion to the limit, the technique is useful for advanced quantum control protocols such as error mitigation schemes, where fast qubit parameter calibration with a large signal-to-noise ratio is crucial.
