Golias E, Kumberg I, Gelen I, Thakur S, Gördes J, Hosseinifar R, Guillet Q, Dewhurst J K, Sharma S, Schüßler-Langeheine C, Pontius N, Kuch W
Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany.
Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, 06120 Halle, Germany.
Phys Rev Lett. 2021 Mar 12;126(10):107202. doi: 10.1103/PhysRevLett.126.107202.
We present evidence for an ultrafast optically induced ferromagnetic alignment of antiferromagnetic Mn in Co/Mn multilayers. We observe the transient ferromagnetic signal at the arrival of the pump pulse at the Mn L_{3} resonance using x-ray magnetic circular dichroism in reflectivity. The timescale of the effect is comparable to the duration of the excitation and occurs before the magnetization in Co is quenched. Theoretical calculations point to the imbalanced population of Mn unoccupied states caused by the Co interface for the emergence of this transient ferromagnetic state.
我们展示了关于在Co/Mn多层膜中反铁磁Mn的超快光诱导铁磁取向的证据。我们利用反射率中的x射线磁圆二色性，在泵浦脉冲到达Mn L₃共振处时观察到瞬态铁磁信号。该效应的时间尺度与激发持续时间相当，且发生在Co中的磁化被淬灭之前。理论计算表明，这种瞬态铁磁态的出现是由Co界面导致的Mn未占据态的不平衡占据引起的。
