Department of Physics, New York University, 4 Washington Place, New York, New York 10003, USA.
Grup de Magnetisme, Departament de Física Fonamental, Universitat de Barcelona, Barcelona 08028, Spain.
Phys Rev Lett. 2015 Sep 18;115(12):127205. doi: 10.1103/PhysRevLett.115.127205. Epub 2015 Sep 17.
We report the direct observation of a localized magnetic soliton in a spin-transfer nanocontact using scanning transmission x-ray microscopy. Experiments are conducted on a lithographically defined 150 nm diameter nanocontact to an ultrathin ferromagnetic multilayer with perpendicular magnetic anisotropy. Element-resolved x-ray magnetic circular dichroism images show an abrupt onset of a magnetic soliton excitation localized beneath the nanocontact at a threshold current. However, the amplitude of the excitation ≃25° at the contact center is far less than that predicted (⪅180°), showing that the spin dynamics is not described by existing models.
我们利用扫描透射 X 射线显微镜直接观察到了自旋转移纳米触点中的局域磁孤子。实验是在一个光刻定义的直径为 150nm 的纳米触点到具有垂直磁各向异性的超薄铁磁多层上进行的。元素分辨的 X 射线磁圆二色图像显示，在一个阈值电流下，在纳米触点下方局域的磁孤子激发突然出现。然而，在接触中心的激发幅度 ≃25°远小于预测值（⪅180°），表明自旋动力学不能用现有模型来描述。
