论文标题
多级量子噪声光谱
Multi-level Quantum Noise Spectroscopy
论文作者
论文摘要
系统噪声识别对于鲁棒量子系统的工程至关重要。尽管现有的量子噪声光谱（QNS）协议测量了影响量子系统的总数噪声，但它们通常无法区分有助于它的基础过程。在这里，我们建议并通过实验验证一种基于自旋锁的QNS协议，该协议利用了超导量子轴的多级能结构，以取得两个显着的进步。首先，我们的协议扩展了弱的非谐量子标程光谱仪的光谱范围，超出了由于缺乏强大的非谐调而设定的限制。其次，从探测较高兴奋的级别中获得的其他信息使我们能够识别和区分不同的潜在噪声机制。
System noise identification is crucial to the engineering of robust quantum systems. Although existing quantum noise spectroscopy (QNS) protocols measure an aggregate amount of noise affecting a quantum system, they generally cannot distinguish between the underlying processes that contribute to it. Here, we propose and experimentally validate a spin-locking-based QNS protocol that exploits the multi-level energy structure of a superconducting qubit to achieve two notable advances. First, our protocol extends the spectral range of weakly anharmonic qubit spectrometers beyond the present limitations set by their lack of strong anharmonicity. Second, the additional information gained from probing the higher-excited levels enables us to identify and distinguish contributions from different underlying noise mechanisms.
