Transient band structures in the ultrafast demagnetization of ferromagnetic gadolinium and terbium
Transient band structures in the ultrafast demagnetization of ferromagnetic gadolinium and terbium
复制标题
铁磁钆和铽超快退磁中的瞬态能带结构
DOI：
10.1103/physrevb.91.014425
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发表时间：
2015
影响因子：
3.7
通讯作者：
M. Weinelt
中科院分区：
文献类型：
--
作者：
M. Teichmann;B. Frietsch;K. Döbrich;R. Carley;M. Weinelt
我们比较激光驱动的稀土钆和铽的退磁动力学映射其瞬态价带结构与时间和角度分辨光电子能谱。在这两种金属中，少数和多数自旋价带在光激发后以不同的时间常数独立地演化。部分未被占用的少数自旋体带的超快位移到更高的结合能和大多数自旋表面态的结合能较低表明表面和体之间的自旋输运。完全占据的多数自旋带的较慢响应遵循晶格温度，并归因于Elliott-Yafet型自旋翻转散射。铽显示出更强和更快的交换分裂衰减，指向超快磁振子发射通过自旋-晶格耦合。
We compare the laser-driven demagnetization dynamics of the rare earths gadolinium and terbium by mapping their transient valance band structures with time- and angle-resolved photoelectron spectroscopy. In both metals, the minority and majority spin valence bands evolve independently with different time constants after optical excitation. The ultrafast shift of the partially unoccupied minority spin bulk band to higher binding energy and of the majority spin surface state to lower binding energy suggests spin transport between surface and bulk. The slower response of the fully occupied majority spin band follows the lattice temperature and is attributed to Elliott-Yafet type spin-flip scattering. Terbium shows a stronger and faster decay of the exchange splitting, pointing to ultrafast magnon emission viaspin-to-lattice coupling.