Becker J, Tsukamoto A, Kirilyuk A, Maan J C, Rasing Th, Christianen P C M, Kimel A V
Radboud University, Institute for Molecules and Materials, Nijmegen 6525 AJ, The Netherlands.
High Field Magnet Laboratory (HFML-EMFL), Radboud University, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands.
Phys Rev Lett. 2017 Mar 17;118(11):117203. doi: 10.1103/PhysRevLett.118.117203. Epub 2017 Mar 14.
We show that applying magnetic fields up to 30 T has a dramatic effect on the ultrafast spin dynamics in ferrimagnetic GdFeCo. Upon increasing the field beyond a critical value, the dynamics induced by a femtosecond laser excitation strongly increases in amplitude and slows down significantly. Such a change in spin response is explained by different dynamics of the Gd and FeCo magnetic sublattices following a spin-flop phase transition from a collinear to a noncollinear spin state.
我们表明，施加高达30 T的磁场对亚铁磁性GdFeCo中的超快自旋动力学有显著影响。当磁场增加超过临界值时，飞秒激光激发所诱导的动力学在幅度上大幅增加且显著减慢。自旋响应的这种变化可通过Gd和FeCo磁性亚晶格从共线自旋态到非共线自旋态的自旋翻转相变后的不同动力学来解释。
