报告题目：Quantum nonlinear oscillations and quantum synchronization in open quantum systems
报告人：A.Prof. Yuzuru Kato（Future University Hakodate）
报告时间：2024年11月14日（周四）上午10:00-11:20
主办单位：必威西汉姆官网平台、航空航天结构力学及控制全国重点实验室、国际合作处
报告内容摘要：
Quantum synchronization is a burgeoning research area studying synchronization phenomena in open quantum systems. This talk overviews the recent development of quantum synchronization, presents a general theoretical framework for analyzing nonlinear dynamics in the phase space of the quasiprobability distributions for open quantum systems, and introduces some of our recent works related to quantum nonlinear oscillations and quantum synchronization. In the first part, we introduce a semiclassical phase reduction to analyze quantum synchronization. In our framework, the dynamics of open quantum systems exhibiting limit-cycle oscillations are reduced to a simple, one-dimensional classical stochastic differential equation approximately describing the phase dynamics of the system under the semiclassical approximation. This framework enables us to analyze synchronization dynamics of quantum limit-cycle oscillators using the standard methods for classical limit-cycle oscillators in a quantitative way. In the second part, we introduce quantum coherence resonance phenomena in a quantum excitable system. We first demonstrate that quantum coherence resonance occurs in the semiclassical regime, namely, the regularity of the system’s oscillatory response is maximized at an optimal intensity of quantum fluctuations, and interpret this phenomenon by analogy with classical noisy excitable systems using semiclassical stochastic differential equations. We further investigate the stronger quantum regimes and demonstrate that the regularity of the system’s response can exhibit the second peak as the intensity of the quantum fluctuations is further increased. We show that this second peak of resonance is a strong quantum effect that cannot be interpreted by a semiclassical picture, in which only a few energy states participate in the system dynamics.
报告人简介：
Dr. Yuzuru Kato is an associate professor at Future University Hakodate. He received his PhD degree in Engineering from Tokyo Institute of Technology in 2020. He was a JST research fellow and a JSPS research fellow from 2020 to 2022. Since 2022, he has been an associate professor at School of Systems Information Science, at Future University Hakodate. He also won the Edward N. Lorenz Early Career Awards from Chaos in 2022. His main research interests include nonlinear dynamics and mathematical engineering, particularly in the open quantum systems.
