论文标题
铁磁三层中手性域壁的不对称含量
Asymmetric depinning of chiral domain walls in ferromagnetic trilayers
论文作者
论文摘要
我们表明，可以使用非磁性间隔物分离的两个铁磁层之间的耦合可以用于控制域壁的占倒数并诱导单向域壁的传播。我们研究了COFEB/TI/COFEB Trilayers，其中顶部COFEB层磁化的易于轴是平面外的，底层的面积为内。使用磁化kerr效应显微镜，我们发现垂直磁化的COFEB层中域壁的含量受平面层的磁化方向的影响，这会引起现场驱动的非对称域的扩展。这种效果是由于域壁的内部磁化和平面内COFEB层的磁化而产生的，这破坏了垂直COFEB层中的上下和向上的同骨Néel区域壁的对称性。微磁模拟通过表明层间耦合反对或有利于域壁中的dzyaloshinskii-moriya相互作用来支持这些发现，从而在下降场中产生不平衡。这种效果还允许人为地控制缺乏强大dzyaloshinskii-moriya相互作用的磁层中的域壁的手性和动力学。
We show that the coupling between two ferromagnetic layers separated by a nonmagnetic spacer can be used to control the depinning of domain walls and induce unidirectional domain wall propagation. We investigated CoFeB/Ti/CoFeB trilayers where the easy axis of the magnetization of the top CoFeB layer is out-of-plane and that of the bottom layer is in-plane. Using Magneto-optic Kerr effect microscopy, we find that the depinning of a domain wall in the perpendicularly magnetized CoFeB layer is influenced by the orientation of the magnetization of the in-plane layer, which gives rise to a field-driven asymmetric domain expansion. This effect occurs due to the magnetic coupling between the internal magnetization of the domain wall and the magnetization of the in-plane CoFeB layer, which breaks the symmetry of up-down and down-up homochiral Néel domain walls in the perpendicular CoFeB layer. Micromagnetic simulations support these findings by showing that the interlayer coupling either opposes or favors the Dzyaloshinskii-Moriya interaction in the domain wall, thereby generating an imbalance in the depinning fields. This effect also allows for artificially controlling the chirality and dynamics of domain walls in magnetic layers lacking a strong Dzyaloshinskii-Moriya interaction.
