Miedaner Peter R, Berndt Nadia, Deschamps Jude, Urazhdin Sergei, Khatu Nupur, Fainozzi Danny, Brioschi Marta, Carrara Pietro, Cucini Riccardo, Rossi Giorgio, Wittrock Steffen, Ksenzov Dmitriy, Mincigrucci Riccardo, Bencivenga Filippo, Foglia Laura, Paltanin Ettore, Bonetti Stefano, Engel Dieter, Schick Daniel, Gutt Christian, Comin Riccardo, Nelson Keith A, Maznev Alexei A
Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA.
Department of Physics, Emory University, Atlanta, GA, USA.
Sci Adv. 2024 Sep 6;10(36):eadp6015. doi: 10.1126/sciadv.adp6015.
The advent of free electron lasers has opened the opportunity to explore interactions between extreme ultraviolet (EUV) photons and collective excitations in solids. While EUV transient grating spectroscopy, a noncollinear four-wave mixing technique, has already been applied to probe coherent phonons, the potential of EUV radiation for studying nanoscale spin waves has not been harnessed. Here we report EUV transient grating experiments with coherent magnons in Fe/Gd ferrimagnetic multilayers. Magnons with tens of nanometers wavelengths are excited by a pair of femtosecond EUV pulses and detected via diffraction of a probe pulse tuned to an absorption edge of Gd. The results unlock the potential of nonlinear EUV spectroscopy for studying magnons and provide a tool for exploring spin waves in a wave vector range not accessible by established inelastic scattering techniques.
自由电子激光器的出现为探索极紫外（EUV）光子与固体中的集体激发之间的相互作用提供了机会。虽然EUV瞬态光栅光谱法（一种非共线四波混频技术）已被用于探测相干声子，但EUV辐射在研究纳米级自旋波方面的潜力尚未得到利用。在此，我们报告了在铁/钆亚铁磁多层膜中利用相干磁振子进行的EUV瞬态光栅实验。具有数十纳米波长的磁振子由一对飞秒EUV脉冲激发，并通过调谐到钆吸收边缘的探测脉冲的衍射进行检测。这些结果开启了非线性EUV光谱法在研究磁振子方面的潜力，并提供了一种工具，用于探索既定非弹性散射技术无法触及的波矢范围内的自旋波。
