论文标题
形状各向异性在磁性纳米线中热梯度驱动域壁动力学上的作用
Role of shape anisotropy on thermal gradient-driven domain wall dynamics in magnetic nanowires
论文作者
论文摘要
我们研究了热梯度(TG)下单轴/双轴纳米线中的磁性域壁(DW)动力学。研究结果表明,DW在两种纳米线中都向更热的区域传播。这种观察的主要物理学是宏伟的角动量转移到DW。硬(形状)各向异性存在于双轴纳米线中,从而贡献了额外的扭矩,因此DW速度大于单轴纳米线的速度。通过较低的阻尼,DW速度较小,而DW速度随着阻尼而增加,这与通常的期望相反。为了解释这一点,可以预测,如果热产生的自旋波的传播长度大于纳米线的长度,则可能会形成站立自旋波(不携带净能量/动量)以及行进的自旋波。对于较大的阻尼,DW随着阻尼而减小,因为镁繁殖长度会降低。因此,以上发现可能在实现Spintronic(赛道内存)设备方面有用。
We investigate the magnetic domain wall (DW) dynamics in uniaxial/biaxial nanowires under a thermal gradient (TG). The findings reveal that the DW propagates toward the hotter region in both nanowires. The main physics of such observations is the magnonic angular momentum transfer to the DW. The hard (shape) anisotropy exists in biaxial nanowire, which contributes an additional torque, hence DW speed is larger than that in uniaxial nanowire. With lower damping, the DW velocity is smaller and DW velocity increases with damping which is opposite to usual expectation. To explain this, it is predicted that there is a probability to form the standing spin-waves (which do not carry net energy/momentum) together with travelling spin-waves if the propagation length of thermally-generated spin-waves is larger than the nanowire length. For larger-damping, DW decreases with damping since the magnon propagation length decreases. Therefore, the above findings might be useful in realizing the spintronic (racetrack memory) devices.