论文标题
镁磁性绝缘子中的180 $^\ circ $域墙的存在的令人困惑的不敏感性
A puzzling insensitivity of magnon spin diffusion to the presence of 180$^\circ$ domain walls in a ferrimagnetic insulator
论文作者
论文摘要
我们介绍了室温测量的木旋旋扩散中的木旋磁扩散剂Mgal $ _ {0.5} $ _ {1.5} $ _ {1.5} $ o $ $ _ {4} $（mafo）薄膜附近零施加的磁场，样品构成了多层状态。由于单轴磁各向异性弱，该结构域主要分离为180 $^\ Circ $域壁。我们发现，令人惊讶的是，域壁的存在对自旋扩散几乎没有影响 - 多域状态中的非局部自旋传输信号保留了至少距离典型域大小的距离至少五倍的距离五倍。该结果与镁与静态域壁之间的简单相互作用模型发生冲突，该模型预测，镁化的旋转极化会在通过180美元$^\ Circ $域壁上逆转。
We present room-temperature measurements of magnon spin diffusion in epitaxial ferrimagnetic insulator MgAl$_{0.5}$Fe$_{1.5}$O$_{4}$ (MAFO) thin films near zero applied magnetic field where the sample forms a multi-domain state. Due to a weak uniaxial magnetic anisotropy, the domains are separated primarily by 180$^\circ$ domain walls. We find, surprisingly, that the presence of the domain walls has very little effect on the spin diffusion -- nonlocal spin transport signals in the multi-domain state retain at least 95% of the maximum signal strength measured for the spatially-uniform magnetic state, over distances at least five times the typical domain size. This result is in conflict with simple models of interactions between magnons and static domain walls, which predict that the spin polarization carried by the magnons reverses upon passage through a 180$^\circ$ domain wall.
