论文标题
CU $ _2 $ OSEO $ _3 $的旋转激发的时间分辨测量
Time-resolved measurement of spin excitations in Cu$_2$OSeO$_3$
论文作者
论文摘要
与检测到的铁磁共振（DFMR）结合使用的磁衍射是对单个自旋纹理进行时间分辨测量的强大技术。在这里，我们研究了手性磁铁Cu $ _2 $ oseo $ _3 $中的锥形和田间偏振相的铁磁共振（FMR）模式。使用宽带矢量网络分析仪FMR鉴定FMR模式后，我们在晶体（001）Bragg峰上使用DFMR来揭示所选FMR模式的时间依赖性的自旋配置。通过能够测量整个共振的自旋系统的振幅和相位响应，在锥形模式下（180 $^\ circ $）的连续相位前进，以及在现场极化模式下的相位滞后（180 $^\ circ $）。通过在圆锥形相中执行动态测量，这是X射线线性极化角的函数，即依次探测矩的动力学，我们发现在倒置的场方向时沿圆锥形轴的动力学反转。通过允许对单个磁相的相位和幅度进行时间分辨的测量，DFMR为对手性磁体的复杂动力学有了更深入的了解开辟了新的机会。
Magnetic diffraction in combination with x-ray detected ferromagnetic resonance (DFMR) is a powerful technique for performing time-resolved measurements on individual spin textures. Here, we study the ferromagnetic resonance (FMR) modes of both the conical and field-polarized phases in the chiral magnet Cu$_2$OSeO$_3$. Following the identification of the FMR modes at different temperatures using broadband vector network analyzer FMR, we use DFMR on the crystalline (001) Bragg peak to reveal the time-dependent spin configurations of the selected FMR modes. By being able to measure both the amplitude and phase response of the spin system across the resonance, a continuous phase advance (of 180$^\circ$) in the conical mode, and a phase lag (of 180$^\circ$) in the field-polarized mode is found. By performing dynamic measurements in the conical phase as a function of the linear polarization angle of the x-rays, i.e., successively probing the dynamics of the moments, we find an inversion of the dynamics along the conical axis upon inverting the applied field direction. By allowing for time-resolved measurements of the phase and amplitude of individual magnetic phases, DFMR opens up new opportunities for obtaining a deeper understanding of the complex dynamics of chiral magnets.
