We present an exact analytical solution of the anisotropic Hopfield model, and we use it to investigate in detail the spectral and thermometric response of two ultrastrongly coupled quantum systems. Interestingly, we show that depending on the initial state of the coupled system, the vacuum Rabi splitting manifests significant asymmetries that may be considered spectral signatures of the counterintuitive decoupling effect. Using the coupled system as a thermometer for quantum thermodynamics applications, we obtain the ultimate bounds on the estimation of temperature that remain valid in the ultrastrong coupling regime. Remarkably, if the system performs a quantum phase transition, the quantum Fisher information exhibits periodic divergences, suggesting that one can have several points of arbitrarily high thermometric precision for such a critical quantum sensor.
Resonant Raman scattering of single molecules under strong cavity coupling and ultrastrong optomechanical coupling in plasmonic resonators: phonon-dressed polaritons
Ultrastrong Coupling and Coherent Dynamics in a Gate-Tunable Transmon Qubit
Universidad Autónoma de Madrid（马德里自治大学）；Condensed Matter Physics Center (IFIMAC) and Instituto Nicolás Cabrera (INC), Universidad Autónoma de Madrid（凝聚态物理中心（IFIMAC）和尼古拉斯·卡布雷拉研究所（INC），马德里自治大学）；Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid（凝聚态物理学系，马德里自治大学）；Departamento de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid（凝聚态理论物理学系，马德里自治大学）；Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Científicas (CSIC)（马德里材料科学研究所（ICMM），西班牙国家研究委员会（CSIC））；Laboratorio de Transporte Cuántico, Unidad Asociada UAM/ICMM-CSIC, Madrid（量子输运实验室，UAM/ICMM-CSIC联合单位，马德里）；QuTech and Kavli Institute of Nanoscience, Delft University of Technology（QuTech和卡弗里纳米科学研究所，代尔夫特理工大学）；Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen（量子器件中心，尼尔斯·玻尔研究所，哥本哈根大学）
Frequency-resolved N-photon correlations in the ultra-strong coupling regime
School of Physics and Hubei Key Laboratory of Gravitation and Quantum Physics, Huazhong University of Science and Technology（华中科技大学物理学院与引力与量子物理湖北省重点实验室）；College of Physics, Sichuan University（四川大学物理学院）
研究强耦合腔量子电动力学系统中频率分辨 N 光子相关性，揭示多光子抗聚束和聚束现象，展示对称性在光-物质相互作用中的作用。
