We report numerical simulations of large-amplitude oscillations of a trapped vortex line under a strong ac magnetic field $H(t)=Hsin\omega t$ parallel to the surface. The power dissipated by an oscillating vortex segment driven by the surface ac Meissner currents was calculated by taking into account the nonlinear vortex line tension, vortex mass and a nonlinear Larkin-Ovchinnikov (LO) viscous drag coefficient $\eta (v)$. We show that the LO decrease of $\eta (v)$ with the vortex velocity $v$ can radically change the field dependence of the surface resistance $R_i(H)$ caused by trapped vortices. At low frequencies $R_i(H) $ exhibits a conventional increases with $H$, but as $\omega$ increases, the surface resistance becomes a nonmonotonic function of $H$ which {} with $H$ at higher fields. The effects of frequency, pin spacing and the mean free path $l_i $ on the field dependence of $R_{i}(H) $ were calculated. It is shown that, as the surface gets dirtier and $l_i$ decreases, the anomalous drop of $ R_{i}(H) $ with $H$ shifts to lower fields which can be much smaller than the lower critical magnetic field. Our numerical simulations also show that the LO decrease of $\eta (v)$ with $v$ can cause a vortex bending instability at high field amplitudes and frequencies, giving rise to the formation of dynamic kinks along the vortex. Measurements of $R_i(H)$ caused by sparse vortices trapped perpendicular to the surface can offer opportunities to investigate an extreme nonlinear dynamics of vortices driven by strong current densities up to the depairing limit at low temperatures. The behavior of $R_i(H)$ which can be tuned by varying the rf frequency or concentration of nonmagnetic impurities is not masked by strong heating effects characteristic of dc or pulse transport measurements.

中文翻译：

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强时变迈斯纳电流驱动的曲线涡旋的非线性动力学和耗散

我们报告了在强交流磁场下被困涡流线大振幅振荡的数值模拟 $H（Ť）=H罪\omega Ť$平行于表面。考虑到涡旋线的非线性张力，涡旋质量和非线性拉金-奥夫尼尼科夫（LO）粘性阻力系数，计算了由表面交流Meissner电流驱动的振荡涡流段所消耗的功率$\eta （v）$。我们证明LO的降低$\eta （v）$ 旋涡速度 $v$ 可以从根本上改变表面电阻的场依存性 ${\mathrm{[R}}_{\mathrm{一世}}（H）$由被困的涡流引起。在低频$ R_i（H）$具有常规的增加$H$，但作为 $\omega$ 增大，表面电阻变为非单调函数 $H$ 其中{}与 $H$在更高的领域。计算了频率，引脚间距和平均自由程$ l_i $对$ R_ {i}（H）$的场依赖性的影响。结果表明，随着表面变脏，${升}_{\mathrm{一世}}$ 减少，$ R_ {i}（H）$的异常下降 $H$移到可能比临界磁场低得多的较低磁场。我们的数值模拟还表明LO的降低$\eta （v）$ 与 $v$会在高场振幅和频率下引起涡旋弯曲不稳定性，从而导致沿涡旋形成动态扭结。的测量${\mathrm{[R}}_{\mathrm{一世}}（H）$垂直于表面的稀疏涡流所引起的涡流可以提供机会研究涡流的极端非线性动力学，该涡流是由强电流密度驱动的，直至在低温下达到破坏极限。的行为${\mathrm{[R}}_{\mathrm{一世}}（H）$ 可以通过改变射频频率或调整非磁性杂质的浓度进行调节，但不能被直流或脉冲传输测量的强热效应所掩盖。