One of the fundamental tasks in quantum metrology is to estimate multiple parameters embedded in a noisy process, i.e., a quantum channel. In this paper, we study fundamental limits to quantum channel estimation via the concept of amortization and the right logarithmic derivative (RLD) Fisher information value. Our key technical result is the proof of a chain-rule inequality for the RLD Fisher information value, which implies that amortization, i.e., access to a catalyst state family, does not increase the RLD Fisher information value of quantum channels. This technical result leads to a fundamental and efficiently computable limitation for multiparameter channel estimation in the sequential setting, in terms of the RLD Fisher information value. As a consequence, we conclude that if the RLD Fisher information value is finite, then Heisenberg scaling is unattainable in the multiparameter setting.
Multiparameter Quantum Estimation Theory in Quantum Gaussian states
多参数量子估计理论旨在同时确定给定量子系统态中所有参数的最终精度。确定这一最终精度取决于量子费舍尔信息矩阵（QF），这是必不可少的，以获得量子克拉美-拉奥界。这是这项工作的主要动机，其中涉及的QESTs的解析表达式的计算。受J. Phys. A 52，035304（2019）中报道的结果的启发，给出了量子高斯态的多参数量子估计理论的一阶矩和二阶矩的一般形式。给出了右对数导数（RLD）和对称对数导数（SLD）算子的解析公式。在此基础上，我们导出了相应的量子费舍尔信息矩阵的一般表达式。我们还导出了一个明确的表达式的条件，确保饱和的量子克拉美-饶界估计几个参数。最后，我们研究了一些例子，以阐明我们的结果的使用
Bayesian Monotone Metrics for Multiparameter Quantum Estimation
Graduate School of Informatics and Engineering, The University of Electro-Communications（电气通信大学信息工程学院）；Institute of Science and Engineering, Kanazawa University（金泽大学理工研究院）
Deciding the Attainability of the Multiparameter Quantum Fisher Information is NP-Hard
Joint Quantum Institute, NIST/University of Maryland（美国国家标准与技术研究院/马里兰大学联合量子研究所）；Joint Center for Quantum Information and Computer Science, NIST/University of Maryland（美国国家标准与技术研究院/马里兰大学量子信息与计算科学联合中心）；Centre for Quantum Technologies (CQT), National University of Singapore（新加坡国立大学量子技术中心）；Quantum Innovation Centre (Q.InC), Agency for Science, Technology and Research (A*STAR)（科学技术研究局量子创新中心）；UMIACS, University of Maryland（马里兰大学计算机科学与信息系统多学科研究中心）；Center for Quantum Software and Innovation, University of Technology Sydney（悉尼科技大学量子软件与创新中心）；Department of Quantum Science and Technology, Research School of Physics, The Australian National University（澳大利亚国立大学物理研究学院量子科学与技术系）；Axiomatic AI, Inc.（公理人工智能公司）；Graduate School of Informatics and Engineering, The University of Electro-Communications（电气通信大学信息工程学研究生院）
Uncertainty relations between quantum Fisher information and entanglement monotones
State key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Frontiers Science Center for Nano-optoelectronics, Peking University（北京大学物理学院前沿纳米光电交叉研究中心人工微结构与介观物理国家重点实验室）；Department of Physics, ETH Zürich（苏黎世联邦理工学院物理系）；Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien（维也纳工业大学原子研究所维也纳量子科学与技术中心）；Collaborative Innovation Center of Extreme Optics, Shanxi University（山西大学极端光学协同创新中心）；Hefei National Laboratory（合肥国家实验室）
Semi-classical geometric tensor in multiparameter quantum information
University of Tsukuba（筑波大学）；Center for Artificial Intelligence Research (C-AIR), University of Tsukuba（筑波大学人工智能研究中心）；Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (CNR-INO)（意大利国家光学研究所）；European Laboratory for Nonlinear Spectroscopy (LENS)（欧洲非线性光谱学实验室）；Zhejiang University（浙江大学）；Nordita, KTH Royal Institute of Technology and Stockholm University（诺迪塔，瑞典皇家理工学院与斯德哥尔摩大学）
Geometric bounds on multiparameter Heisenberg scaling in optical metrology with limited squeezed resources
University of Portsmouth（朴茨茅斯大学）；Quantum Science and Technology Hub, University of Portsmouth（朴茨茅斯大学量子科学与技术中心）；Università di Bari（巴里大学）；INFN, Sezione di Bari（意大利国家核物理研究所巴里分部）；Institute of Cosmology and Gravitation, University of Portsmouth（朴茨茅斯大学宇宙学与引力研究所）
Error-corrected function estimation advantage in multiparameter Hamiltonians
Joint Center for Quantum Information and Computer Science, National Institute of Standards and Technology and University of Maryland（量子信息与计算联合中心，美国国家标准与技术研究院和马里兰大学）；Joint Quantum Institute, National Institute of Standards and Technology and University of Maryland（联合量子研究所，美国国家标准与技术研究院和马里兰大学）；Volgenau Department of Physics, United States Naval Academy（沃尔格瑙物理系，美国海军学院）
Optimal multiparameter quantum estimation in accelerating Unruh-DeWitt detectors
Mohammed V University in Rabat（拉巴特穆罕默德五世大学）；Ibnou Zohr University（伊本·佐哈尔大学）；Princess Nourah bint Abdulrahman University（公主努拉·宾特·阿卜杜勒拉赫曼大学）；University of Bisha（比沙大学）
Approaching the Limit in Multiparameter AC Magnetometry with Quantum Control
Research Laboratory of Electronics, Massachusetts Institute of Technology（麻省理工学院电子研究实验室）；Department of Nuclear Science and Engineering, Massachusetts Institute of Technology（麻省理工学院核科学与工程系）；Pritzker School of Molecular Engineering, The University of Chicago（芝加哥大学普里茨克分子工程学院）；Department of Electrical and Electronic Engineering, Institute of Science Tokyo（东京科学大学电气与电子工程系）；Department of Physics, Massachusetts Institute of Technology（麻省理工学院物理系）；Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong（香港科技大学机械与自动化工程系）；Department of Physics, The University of Tokyo（东京大学物理系）
Visibility-Engineered Multiparameter Sensing in Dispersive Quantum Interferometry: Identifiability, Noise Robustness, and Hardware Emulation
Instituto de Física, Universidade Federal de Goiás（戈亚斯联邦大学物理研究所）；Faculty of Civil Engineering and Mechanics, Kunming University of Science and Technology（昆明理工大学土木工程学院）；Instituto de Física de São Carlos, Universidade de São Paulo（圣保罗大学圣卡洛斯物理研究所）
Heisenberg-scaling characterization of a two-channel optical network via two-port homodyne detection
School of Mathematics and Physics, University of Portsmouth（朴茨茅斯大学数学与物理学院）；Quantum Science and Technology Hub, University of Portsmouth（朴茨茅斯大学量子科学与技术中心）；Dipartimento di Fisica, Università di Bari & Politecnico di Bari（巴里大学与巴里理工大学物理系）；INFN, Sezione di Bari（意大利国家核物理研究所巴里分部）；Institute of Cosmology and Gravitation, University of Portsmouth（朴茨茅斯大学宇宙学与引力研究所）
Attaining Fundamental Limits of Multiparameter Incoherent Optical Imaging Using Joint-Detection Quantum Measurements
Wyant College of Optical Sciences, University of Arizona（亚利桑那大学怀特光学科学学院）；Clarendon Laboratory, University of Oxford（牛津大学克拉伦登实验室）；Physical Sciences and Systems, Raytheon BBN（雷神BBN物理科学与系统部门）；Department of Electrical and Computer Engineering, University of Maryland（马里兰大学电气与计算机工程系）
