We develop a new master equation as a unified description of the effects of both quantum noise (system-bath interaction) and classical noise on a system's dynamics, using a two-dimensional series expansion method. When quantum and classical noises are both present, their combined effect on a system's dynamics is not necessarily a simple sum of the two individual effects. Thus previous master equations for open systems and those for classical noise, even when jointly used, may not capture the full physics. Our formalism can determine whether there is interference between quantum and classical noises and will be able to capture and describe such interference if there is any (in a perturbative manner). We find that, interestingly, second-order interference between quantum and classical noises vanishes identically. This work thus also serves to justify simple additive treatments of quantum and classical noises, especially in the weak coupling regime. For a Zeeman-splitted atom in a stochastic magnetic field interacting with an optical cavity, we use the formalism developed herein to find the overall decoherence rate between the atom's energy levels.
Unifying Finite-Temperature Dynamical and Excited-State Quantum Phase Transitions
Instituto de Estructura de la Materia, IEM-CSIC（物质结构研究所，西班牙国家科学研究委员会）；Grupo Interdisciplinar de Sistemas Complejos (GISC), Universidad Complutense de Madrid（马德里康普顿斯大学复杂系统跨学科小组）；Departamento de Estructura de la Materia, Física Térmica y Electrónica, Universidad Complutense de Madrid（马德里康普顿斯大学物质结构、热学和电子学系）；Department of Physics and Arnold Sommerfeld Center for Theoretical Physics (ASC), Ludwig-Maximilians-Universität München（慕尼黑大学物理系与阿诺德·索末菲理论物理中心）；Munich Center for Quantum Science and Technology (MCQST)（慕尼黑量子科学与技术中心）；Dahlem Center for Complex Quantum Systems, Freie Universität Berlin（柏林自由大学达勒姆复杂量子系统中心）
Geometric Meta-Learning via Coupled Ricci Flow: Unifying Knowledge Representation and Quantum Entanglement
School of Aeronautics and Astronautics, Shanghai Jiao Tong University（上海交通大学航空航天学院）；Météo-France（法国气象局）；CNRS（法国国家科学研究中心）；Mathematical Institute of Toulouse（图卢兹数学研究所）
