We study Nielsen's circuit complexity in a periodic harmonic oscillator chain, under single and multiple quenches. In a multiple quench scenario, it is shown that the complexity shows remarkably different behaviour compared to the other information theoretic measures, such as the entanglement entropy. In particular, after two successive quenches, when the frequency returns to its initial value, there is a lower limit of complexity, which cannot be made to approach zero. Further, we show that by applying a large number of successive quenches, the complexity of the time evolved state can be increased to a high value, which is not possible by applying a single quench. This model also exhibits the interesting phenomenon of crossover of complexities between two successive quenches performed at different times.
JCO: Optimization Framework for Nonlinear Superconducting Circuits Using a Lumped-Element Approach and Harmonic Balance
Politecnico di Torino（都灵理工大学）；INRiM - Istituto Nazionale di Ricerca Metrologica（意大利国家计量研究所）；University of Palermo（巴勒莫大学）；CNIT, RaSS（国家光纤通信与系统研究中心，射频与传感实验室）
Circuit Harmonic Matrices: A Spectral Framework for Quantum Machine Learning
Quantum Software Lab, School of Informatics, The University of Edinburgh（爱丁堡大学信息学院量子软件实验室）；School of Physics and Astronomy, The University of Edinburgh（爱丁堡大学物理与天文学学院）
Microwave degenerate parametric down-conversion with a single cyclic three-level system in circuit QED
利用超导磁通量子比特实现的单循环三能级系统，研究了超导传输线谐振器中包含基波和二次谐波模的简并微波参量下转换（PDC）.通过对三能级系统的激发态进行几何消去，我们得到了这种电路QED系统中两个谐振腔模的有效微波PDC哈密顿量。在我们的模型中相应的PDC效率可以比基于单个二能级超导量子比特的类似电路QED系统中的效率大得多[K. Moon和S. M. Girvin，Phys. Rev. Lett. { \bf 95}，140504（2005）]。此外，我们还考虑了相干驱动二次谐波时基模的压缩和聚束行为。
Information Dynamics in Quantum Harmonic Systems: Insights from Toy Models
School of Quantum Physics and Matter, Institute for Research in Fundamental Sciences (IPM)（基础科学研究所）；Ershad Damavand, Institute of Higher Education (EDI)（厄尔沙德达马万德高等教育研究所）；Department of Physics, Central Tehran Branch, Islamic Azad University (IAU)（伊斯兰阿扎德大学中央德黑兰分校物理系）
Nonlinear Feedback in Josephson Circuit Optimization: Application to a Kerr-Reversal JTWPA
Department of Applied Science and Technology, Politecnico di Torino（都灵理工大学应用科学与技术系）；Quantum Metrology and Nanotechnology Division, Istituto Nazionale di Ricerca Metrologica（意大利国家计量科学研究院量子计量与纳米技术部）；Department of Engineering, University of Palermo（巴勒莫大学工程学院）
