发表机构
Technical University of Munich; Monash University; Agency for Science, Technology and Research (A*STAR); Singapore University of Technology and Design; Centre for Quantum Technologies; MQSC GmbH; Software Competence Center Hagenberg GmbH (SCCH)（慕尼黑工业大学; 蒙纳士大学; 新加坡科技研究局; 新加坡科技设计大学; 量子技术中心; MQSC有限公司; 哈根贝格软件能力中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文针对量子系统受环境影响的问题，提出仅通过系统可控干预和观测的响应矩阵方法，表征环境记忆结构，可并行计算，能诊断相关噪声并测试开放系统模型。
AI 中文摘要
量子系统极少与周围环境完全隔离，这些隐藏环境会保留信息并在后续返回，从而在量子计算机中产生相关误差，并使量子处理器的解释变得复杂。例如，在量子处理器中，一个任务可能会在量子比特自身被重置后仍留下环境痕迹，影响下一个任务。因此，了解这种隐藏影响如何持续并作用于后续行为十分重要，但环境往往无法直接测量，且通过断层扫描完全重构其影响会迅速变得不切实际。本文中，我们引入一种响应矩阵，该矩阵仅通过对系统的可控干预和观测来揭示环境记忆的时间结构，该矩阵记录未来观测如何随不同可控历史变化。其谱特性表征了记忆的结构以及在指定系统重置下的持续方式，而其元素的适当线性组合可排除该记忆的特定经典模型。由于其历史-未来查询可独立评估，数值响应矩阵可并行组装。我们从理论上建立该框架，表征相互作用自旋过程中的响应谱，并在两量子比特基准中验证量子记忆。该方法将系统观测转化为对不可达环境的探测，可支持相关噪声的诊断、开放系统模型的测试以及感知记忆的控制设计。
英文摘要
Quantum systems are rarely isolated from their surroundings. These hidden environments can retain information and return it later, producing correlated errors in quantum computers and complicating the interpretation of experiments.On a quantum processor, for example, one job can therefore leave an environmental trace that affects the next, even after the qubits themselves have been reset. Learning how this hidden influence persists and affects later behavior is therefore important, but the environment is often impossible to measure directly, and fully reconstructing its effects through tomography rapidly becomes impractical. Here, we introduce a response matrix that uses controlled interventions and observations of the system alone to reveal the temporal structure of environmental memory. The matrix records how future observations change across different controlled histories. Its spectrum characterizes how memory is structured and how it persists under specified system resets, while suitable linear combinations of its entries can rule out specified classical models of that memory. Because its history-future queries can be evaluated independently, numerical response matrices can be assembled in parallel. We establish the framework theoretically, characterize response spectra in an interacting spin process, and certify quantum memory in a two-qubit benchmark. This approach turns system observations into a probe of inaccessible environments and could support the diagnosis of correlated noise, tests of open system models, and memory-aware control design.
Comments23 pages (18 main + 5 appendix), 9 figures (7 main + 2 appendix)
