AI 中文总结
研究量子多体系统属性可操作性问题，通过量子电路描述统一相关技术，开发仅从探针读出学习多体属性的协议，证明量子探针优势，其资源与目标关联复杂性有关，提供新学习方法。
AI 中文摘要
量子多体系统的哪些属性在操作上是可访问的，这是光谱学、热力学和量子信息科学的核心问题。传统响应理论在仅系统范式内回答该问题：对物质本身进行微扰和测量，通过因果有序的嵌套对易子获得磁化率。本文表明，相干控制的量子探针在最后测量时，定义了一个比响应理论可访问的更大的操作学习框架。我们通过量子电路描述来建立这一点，该描述将光谱学、探针显微镜和基于探针的量子技术统一在一个通用操作框架内，从中我们开发了仅从探针读出学习多体属性的量子协议。这种优势源于量子探针的简化动力学通常编码目标的反对易子和混合阶关联器；因此，对探针的测量可获取通常通过响应函数或单个探针无法访问的涨落、非平衡结构和纠缠熵。此外，我们证明纠缠探针可以访问诸如冯·诺依曼熵等多体属性。我们证明所需的探针资源与目标关联的复杂性成比例，而不是与多体系统的大小成比例。因此，量子探针不仅是更灵敏的传感器，还提供了一种不同于断层扫描或量子模拟的学习多体属性的新方法。
英文摘要
Which properties of a quantum many-body system are operationally accessible is a central question underlying spectroscopy, thermodynamics, and quantum information science. Conventional response theory answers this question within a system-only paradigm: one perturbs and measures the matter itself, obtaining susceptibility built from causally ordered nested commutators. Here we show that coherently controlled quantum probes, when measured at the end, define a strictly larger operational learning framework beyond that accessible from response theory. We establish this through a quantum-circuit description that unifies spectroscopy, probe microscopy, and probe-based quantum technologies within a common operational framework, from which we develop quantum protocols for learning many-body properties from probe readout only. This advantage arises because the reduced dynamics of quantum probes generically encode anti-commutator and mixed-order correlators of the target; therefore, measurements on the probe provide access to fluctuations, non-equilibrium structure, and entanglement entropy that are in general not accessible through response functions or a single probe alone. Moreover, we demonstrate that entangled probes can access many-body properties such as von Neumann entropy. We prove that the required probe resources scale with the complexity of the target correlations rather than with the size of the many-body system. Quantum probes are therefore not merely more sensitive sensors but provide a new way to learn many-body properties distinct from those of tomography or quantum simulation.
Comments33 pages, 3 figures, 1 Table
