电增益调控的强耦合“腔-磁子极化激元”阻尼抑制的研究

The emerging field of magnon-photon strong coupling system, which generates cavity magnon polariton (CMP), has been recently demonstrated as a promising approach for developing quantum control technique, coherent information processing and spin current manipulation. However, the lack of damping control methods leads to the restriction of applying such polariton dynamics to applications with long coherence time. Currently, such polariton damping parameters at resonant condition are only determined by mean value of uncoupled cavity and magnon mode damping. Therefore, it makes such polariton damping insensitive to extra degree of freedom. Aiming at breaking this limit, in this work we demonstrate that polariton damping control technique can be improved by using a feedback cavity to couple magnon mode. By bring feedback photons back to strongly coupled magnon-photon states, we expect that damping can be controlled continuously by DC voltage in an on-chip device. Moreover, we will demonstrate that goal of dissipation engineering can be observed by varying Rabi frequency, which is previously excluded from conventional magnon-photon damping control. Based on the investigation of damping control mechanism, it is expected in this work that such polariton damping can be suppressed in a quantitative way. Our results will show flexible and precise tuning of damping suppression which may help stimulate the ideas for extending the coherence time in quantum information processing technologies.

光子-磁子的强耦合相互作用是凝聚态物理领域新兴的研究分支，强耦合所形成的“腔-磁子极化激元”展示了其在量子调控、自旋流操控、多模式信息存储方面的重要应用前景。而对耦合态阻尼调控和相应抑制手段的缺乏，限制了耦合态走向长相干时间信息处理的应用。具体为，共振耦合条件下的腔-磁子极化激元阻尼受制于腔和磁子本征耗散的均值，缺乏连续调控的自由度。瞄准该关键点，我们拟在已有反馈腔模中光子-磁子强耦合态色散构筑的基础上，通过电增益向耦合态注入反馈光子，补偿耦合体系损耗，于芯片上实现强耦合态阻尼的连续电调控。并澄清反馈增益腔模中Rabi频率调控阻尼的机理，以此建立耦合阻尼的调控新维度。进而在厘清耦合阻尼调控机制的基础上，利用多场协同调控，实现对强耦合态阻尼的定量抑制。期望以此为长相干时间的信息存储单元器件的研提供建设性的信息。

优势各异的磁子和光子通过强耦合，交换彼此的物理性质，形成准粒子“腔-磁子极化激元”。解决这一耦合动力学阻尼的调控限制，有望推动低损耗的光电子器件及前沿量子信息技术的发展。为此该项目1-突破了耦合态的经典电磁谐振的阻尼调谐限制，以高增益耦合的腔-磁子极化激元形成了对混合态阻尼抑制的新兴调控途径。并进一步以电调谐手段，在片上器件中展示了磁动力学阻尼的多维度灵活调控。2-分别建立了完备的光子-磁子耦合态辐射耗散的微观分析理论，为澄清相干-耗散耦合的连续演化提供了重要依据，为极低阻尼光子-磁子耦合模式的产生提供了基础科学探索。3-操控了二维实空间极化激元输运，挖掘了逻辑运算潜力，文章获Nat. Commun.编辑推荐; 以耦合态阻尼的灵活调谐，构筑了耦合态的完美吸收体，突破了双界面系统的吸收率限制。本项目专注于光子-磁子耦合态研究，形成了有特色的自旋激发及其阻尼的调控和应用拓展工作，相关成果发表于Nat. Commun.等高水平期刊中，对前沿相干信息处理的发展起到了积极的推动作用。