发表机构
University of Seoul; Singularity Quantum Inc（首尔大学; 奇点量子公司）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过相干量子控制揭示环境记忆信息窗口，提出时间尺度匹配原理，用于探测非马尔可夫噪声的有限关联时间。
AI 中文摘要
环境噪声是量子系统中退相干和误差的主要来源。在非马尔可夫环境中，噪声具有有限的关联时间，系统可以保留其先前与环境相互作用的信息。在此，我们研究如何通过有限时长的相干量子操作来观察这种环境记忆。相干控制动态地重塑随机耦合算子，从而改变双时噪声关联对量子过程的影响方式。对于奥恩斯坦-乌伦贝克噪声，我们解析地证明两个不同的极限会减少关于关联时间的信息。在短记忆极限下，主导动力学取决于积分噪声组合σ/τc，其中σ是噪声方差，τc是关联时间，这使得这些参数局部简并。在长记忆极限下，随机场在操作期间变为准静态，对关联时间的敏感性被抑制。对驱动单量子比特Xπ旋转和双量子比特交换门的精确随机模拟表明，当环境和控制时间尺度相当时，独立的关联时间信息在这些极限之间变得最大。非对易控制增强此信息，而对易控制则不然。不同门时长tg的模拟进一步表明，信息窗口近似遵循无量纲关联比τc/tg。这些结果为使用相干量子控制探测有限关联非马尔可夫噪声提供了时间尺度匹配原理。
英文摘要
Environmental noise is a major source of decoherence and errors in quantum systems. In a non-Markovian environment, the noise has a finite correlation time, and the system can retain information about its previous interactions with the environment. Here, we investigate how such environmental memory can be observed through a finite-duration coherent quantum operation. Coherent control dynamically reshapes the stochastic coupling operator and thereby changes how two-time noise correlations affect the quantum process. For Ornstein-Uhlenbeck noise, we show analytically that two different limits reduce the information on the correlation time. In the short-memory limit, the leading dynamics depend on the integrated-noise combination σ/τc, where σ is the noise variance and τc is the correlation time, making these parameters locally degenerate. In the long-memory limit, the stochastic field becomes quasi-static during the operation, and sensitivity to the correlation time is suppressed. Exact stochastic simulations for a driven single-qubit Xπ rotation and a two-qubit exchange gate show that independent correlation-time information becomes largest between these limits, when the environmental and control timescales are comparable. Noncommuting controls enhance this information, whereas commuting controls do not. Simulations at different gate durations tg further show that the information window approximately follows the dimensionless correlation ratio τc/tg. These results provide a timescale-matching principle for probing finite-correlation non-Markovian noise with coherent quantum control.
