论文标题
在几乎PT对称的Ferromagnet中稳定的孤子，带自旋转移扭矩
Stable solitons in a nearly PT-symmetric ferromagnet with spin-transfer torque
论文作者
论文摘要
我们考虑了用于自旋扭矩振荡器的Landau -Lifshitz方程 - 外部磁场中的单轴铁磁体，其偏振旋转电流通过它驱动。在没有吉尔伯特阻尼的情况下，方程式是PT对称的。我们将PT对称性解释为增益和损失之间的平衡 - 并确定获得和丢失模式。在磁化均匀静态状态的分叉点的附近，PT对称的Landau-Lifshitz方程，具有较小的耗散性扰动的pt-Landau-lifshitz方程减少了具有二次非线性的非线性Schrödinger方程。 Schrödinger动力学的分析表明，自旋扭矩振荡器支持稳定的磁孤子。 PT近对准对于孤子稳定性至关重要：在Landau-Lifshitz方程中增加有限的耗散项会破坏我们发现的所有孤子。
We consider the Landau-Lifshitz equation for the spin torque oscillator - a uniaxial ferromagnet in an external magnetic field with polarised spin current driven through it. In the absence of the Gilbert damping, the equation turns out to be PT-symmetric. We interpret the PT-symmetry as a balance between gain and loss - and identify the gaining and losing modes. In the vicinity of the bifurcation point of a uniform static state of magnetisation, the PT-symmetric Landau-Lifshitz equation with a small dissipative perturbation reduces to a nonlinear Schrödinger equation with a quadratic nonlinearity. The analysis of the Schrödinger dynamics demonstrates that the spin torque oscillator supports stable magnetic solitons. The PT near-symmetry is crucial for the soliton stability: the addition of a finite dissipative term to the Landau-Lifshitz equation destabilises all solitons that we have found.
