Chen Jiahui, Niknam Mohamad, Cory David
Institute for Quantum Computing, Waterloo, ON N2L 3G1, Canada.
Department of Physics, University of Waterloo, Waterloo, ON N2L 3G1, Canada.
Entropy (Basel). 2024 Dec 10;26(12):1077. doi: 10.3390/e26121077.
Understanding the flow, loss, and recovery of the information between a system and its environment is essential for advancing quantum technologies. The central spin system serves as a useful model for a single qubit, offering valuable insights into how quantum systems can be manipulated and protected from decoherence. This work uses the stimulated echo experiment to track the information flow between the central spin and its environment, providing a direct measure of the sensitivity of system/environment correlations to environmental dynamics. The extent of mixing and the growth of correlations are quantified through autocorrelation functions of the noise and environmental dynamics, which also enable the estimation of nested commutators between the system/environment and environmental Hamiltonians. Complementary decoupling experiments offer a straightforward measure of the strength of the system Hamiltonians. The approach is experimentally demonstrated on a spin system.
理解系统与其环境之间信息的流动、损失和恢复对于推进量子技术至关重要。中心自旋系统作为单个量子比特的有用模型，为了解如何操纵量子系统以及保护其免受退相干影响提供了有价值的见解。这项工作利用受激回波实验来追踪中心自旋与其环境之间的信息流，直接测量系统/环境相关性对环境动力学的敏感度。混合程度和相关性的增长通过噪声和环境动力学的自相关函数进行量化，这也使得能够估计系统/环境与环境哈密顿量之间的嵌套对易子。互补的去耦实验提供了对系统哈密顿量强度的直接测量。该方法在一个自旋系统上进行了实验验证。
