Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16 Prague 2, Czech Republic.
Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnická 10, 162 00 Praha 6, Czech Republic.
Nat Commun. 2017 May 17;8:15226. doi: 10.1038/ncomms15226.
Domain wall motion driven by ultra-short laser pulses is a pre-requisite for envisaged low-power spintronics combining storage of information in magnetoelectronic devices with high speed and long distance transmission of information encoded in circularly polarized light. Here we demonstrate the conversion of the circular polarization of incident femtosecond laser pulses into inertial displacement of a domain wall in a ferromagnetic semiconductor. In our study, we combine electrical measurements and magneto-optical imaging of the domain wall displacement with micromagnetic simulations. The optical spin-transfer torque acts over a picosecond recombination time of the spin-polarized photo-carriers that only leads to a deformation of the initial domain wall structure. We show that subsequent depinning and micrometre-distance displacement without an applied magnetic field or any other external stimuli can only occur due to the inertia of the domain wall.
超短激光脉冲驱动的畴壁运动是设想中的低功耗自旋电子学的前提，它将磁电子器件中信息的存储与以圆偏振光编码的信息的高速长距离传输结合在一起。在这里，我们证明了入射飞秒激光脉冲的圆偏振可以转换为铁磁半导体中畴壁的惯性位移。在我们的研究中，我们将畴壁位移的电测量和磁光成像与微磁模拟相结合。光学自旋转移力矩的作用时间为自旋极化光生载流子的皮秒复合时间，这仅导致初始畴壁结构的变形。我们表明，由于畴壁的惯性，随后在没有外加磁场或任何其他外部刺激的情况下，只能发生去钉扎和微距离的位移。
