基于反铁磁/人工电磁材料复合结构的强耦合效应，自旋波的太赫兹非线性调控研究

The realization of strong coupling between EM radiation and magnon is a big challenging research in spintronics, which provides an effective method to achieve the spin wave manipulation and coherent control nonlinearly. In this proposal, we propose to explore the strong coupling effect between THz radiation and antiferromagnetic structure, and the nonlinear excitation and quantum control on the spin wave of the hybrid system will be studied systematically. On the one hand, the nonlinear response of spin wave can be realized by the locally magnetic field enhancement, on the other hand, by designing the strong coupling factor between the magnon and THz metamaterials cavity mode, the fundamental mechanism of spin wave dynamics in the hybrid system can be clarified. With intense THz time-domain spectroscopy and THz time-resolved spectroscopy, which enables us to explore nonlinear excitation and nonlinear dynamics of spin waves in RFeO3 crystal; Through this research, we can uncover the physical mechanism of spin wave manipulation based on the magnetic modes coupling effect, and we can also explore the insight into the understanding of the dynamical light-mater interaction. Our study can provide experimental data and theoretical guiding for designing of ultrafast spintronics devices.

利用电磁波辐射与自旋波的强耦合而实现对自旋波的非线性调控一直是一个极具挑战性的前沿课题。本项目提出基于THz波段的人工电磁材料(THz metamaterials)与反铁磁介质（稀土铁氧化物单晶RFeO3）复合结构，探索反铁磁单晶中自旋波的非线性激发和量子调控。一方面基于复合结构的磁场局域化增强效应而实现自旋波的非线性激发和响应；另一方面，研究实现人工电磁材料腔模式与自旋波模式的强耦合效应，探索该复合量子体系的非线性调控物理机制。结合THz时域光谱和THz时间分辨光谱，探索强THz脉冲诱导RFeO3反铁磁自旋波的非线性激发和弛豫动力学过程。并探索强THz诱导磁共振模式耦合与转化、THz波段拉比振荡以及THz诱导电磁感应透明等现象。揭示基于模式耦合效应，THz巨脉冲对自旋极化波的非线性调控的物理机制，并在更深层次上理解光与物质相互作用过程。为超快速自旋电子学器件的设计和研制提供理论借鉴。

太赫兹(THz)电磁波辐射与自旋波的强耦合而实现对自旋波的非线性调控是一个极具挑战性的前沿课题。本课题通过构建基于稀土铁氧化物的THz谐振腔复合结构，实现THz光子与磁振子间的强耦合效应。利用THz光谱研究THz光子与磁振子的杂化元激发准粒子（magnon-poariton）的激发和色散特性；基于THz时域光谱观测到在ErFeO3单晶中磁-磁强耦合效应；基于超快脉冲与铁磁/贵金属异质结、二维磁性材料和拓扑绝缘体等相互作用，实现THz波的高效辐射及对THz辐射波前的被动控制。结合多种THz时域光谱，系统地探索了稀土铁氧化物单晶中自旋波的集体激发，色散，自旋重取向外场控制及自旋波的THz波主动调控制等。进一步地还将THz光谱拓展至拓扑绝缘体和拓扑半金属结构，利用THz光子的低能性和非接触等优点，探索和调控量子材料中拓扑量子态的激发和相变控制。本课题的研究结果为超快自旋电子学器件的设计和研制提供理论借鉴和实现方案。