论文标题
量子控制噪声光谱法最佳抑制
Quantum Control Noise Spectroscopy with Optimal Suppression of Dephasing
论文作者
论文摘要
我们将振幅控制噪声的量子噪声光谱（QN）扩展到设置，在这种设置中，噪声或失调误差对量子动态产生了重大贡献。以前的表征振幅噪声的方法受到其易受低频降低噪声和静态失谐误差的限制，这会淹没目标控制噪声信号并将偏置引入幅度噪声光谱的估计值。为了克服这个问题，我们利用最佳控制来识别振幅控制波形的家族，该家族可最佳地抑制低频散发噪声和令人讨厌的误差，同时保持光谱估计的幅度滤波器中的光谱浓度。通过数值优化发现的波形具有令人惊讶的简单分析形式，包括振荡的正弦波遵守特定振幅和频率约束。在数值模拟的QNS实验中，这些波形表现出了较高的鲁棒性，从而在现有方法被低频驱动噪声和失调误差偏置的方案中准确估算了振幅噪声频谱。
We extend quantum noise spectroscopy (QNS) of amplitude control noise to settings where dephasing noise or detuning errors make significant contributions to qubit dynamics. Previous approaches to characterize amplitude noise are limited by their vulnerability to low-frequency dephasing noise and static detuning errors, which can overwhelm the target control noise signal and introduce bias into estimates of the amplitude noise spectrum. To overcome this problem, we leverage optimal control to identify a family of amplitude control waveforms that optimally suppress low-frequency dephasing noise and detuning errors, while maintaining the spectral concentration in the amplitude filter essential for spectral estimation. The waveforms found via numerical optimization have surprisingly simple analytic forms, consisting of oscillating sine waves obeying particular amplitude and frequency constraints. In numerically simulated QNS experiments, these waveforms demonstrate superior robustness, enabling accurate estimation of the amplitude noise spectrum in regimes where existing approaches are biased by low-frequency dephasing noise and detuning errors.
