论文标题
磁场中多色及其不稳定性中复合域壁的动力学
Dynamics of Composite Domain Walls in Multiferroics in Magnetic Field and Their Instability
论文作者
论文摘要
从理论上讲，我们在多铁材料gdfeo $ {} _ 3 $驱动的磁场$ h $驱动的复合域壁（DW）的动力学上。 Fe和GD旋转的两个抗磁磁序与该系统中的GD-ION位移与低温下的$ C $相互作用，并且我们在数值上模拟了相应的时间依赖性的Ginzburg-Landau方程，其中磁场$ H $ H $ H $ h $ h $ h $ h $ h $ h $ h $ h $ h $ a coupers to fe-spin Order订单参数。我们系统地变化了$ h $和$ c $，并计算磁性DW和磁电磁电dw的固定状态的速度$ v $。 DW Mobility $ v/h $随$ H $增加，并且两种DWS的$ C $都会减少，但两者之间的特性也有所不同。我们还通过扰动理论分析了磁电DW的平滑特性。另一个发现是在大H上的分裂不稳定。当$ C $较大时，磁电动DW将磁电型DW分解为一对磁性DW和电动DW，而当$ C $很小时，磁性DW分裂。复合DW的内部结构随着$ c $和$ h $的增加而变形，并以不同的顺序参数在空间中进行调制。他们的相对距离显示出明显的增强，即接近分裂不稳定性。
We study theoretically the dynamics of composite domain walls (DW) in multiferroic material GdFeO${}_3$ driven by magnetic field $H$. Two antiferromagnetic orders of Fe and Gd spins interact Gd-ion displacement in this system with coupling $c$ at low temperatures, and we have numerically simulated the corresponding time-dependent Ginzburg-Landau equations in which magnetic field $H$ couples to Fe-spin order parameter. We vary $H$ and $c$ systematically and calculate velocity $v$ and inner structure in a stationary state for magnetic DW and magneto-electric DW. DW mobility $v/H$ increases with $H$ and decreases with $c$ for both DWs, but their characteristics differ between the two. We have also studied analytically the smooth characteristics of magneto-electric DW by perturbation theory. Another finding is a splitting instability at large H. A magneto-electric DW splits into a pair of magnetic DW and electric DW when $c$ is large, while a magnetic DW splits when $c$ is small. Internal structure of composite DW deforms with increasing $c$ and $H$, and modulations in different order parameters separate in space. Their relative distances show a noticeable enhancement with approaching the splitting instability.
