Department of Physics, Colorado State University, Fort Collins, Colorado 80523, USA.
Phys Rev Lett. 2012 Jun 22;108(25):257202. doi: 10.1103/PhysRevLett.108.257202. Epub 2012 Jun 19.
Relaxation control in magnetic thin films via thermally induced interfacial spin transfers was demonstrated for the first time. The experiments used a trilayered structure that consisted of an yttrium iron garnet (YIG) thin film grown on a gadolinium gallium garnet substrate and capped with a nanometer-thick Pt layer. As a temperature gradient is applied across the thickness of the structure, there exists a spin angular momentum transfer across the YIG/Pt interface. This spin transfer results in a torque on YIG magnetic moments. The torque can either speed up or slow down the relaxation in the YIG film, depending on the sign of the temperature gradient with respect to the trilayered structure.
首次展示了通过热诱导界面自旋转移来控制磁性薄膜的弛豫。该实验采用了三层结构,包括生长在钆镓石榴石衬底上的钇铁石榴石(YIG)薄膜和覆盖有一层纳米厚 Pt 层。当温度梯度施加在结构的厚度上时,会在 YIG/Pt 界面上产生自旋角动量转移。这种自旋转移会在 YIG 磁矩上产生一个扭矩。这个扭矩可以加速或减缓 YIG 薄膜的弛豫,具体取决于温度梯度相对于三层结构的符号。