The possibility of driving vortex lines with an oscillating magnetic field could be useful in many applications. For example, it can be used for the removal of undesired trapped flux from contactless elements of superconducting devices. We investigate the dynamics of vortex lines in a superconducting film with a ratchet thickness profile driven by an oscillating magnetic field applied parallel to the film. We numerically simulate the dynamics of a single flux line modeled as an elastic string with a variable length. We explore the behavior for different frequencies and amplitudes of the oscillating magnetic field and find several dynamic regimes. For moderate frequencies, the average velocity is finite only within specific amplitude ranges. A notable feature is the presence of extended velocity plateaus, which correspond to regimes when the line moves by integer multiples of the spatial period $w$ during integer multiples of the time period $T$. The transitions to these plateau states are rather steep, especially at low frequencies. The plateau at velocity $w/T$ dominates at intermediate frequencies but vanishes at high frequencies. The onset field amplitude of finite velocity nonmonotonically depends on the frequency and passes through a minimum at a certain frequency value. At low frequencies, the velocity exceeds $w/T$ and progressively increases with the amplitude. These findings provide valuable insights into the dynamic behavior of vortex lines driven by oscillating magnetic field in patterned superconducting films, offering potential pathways for controlling the magnetic flux in superconducting devices.
Directional-dependent thermally activated motion of vortex bundles and theory of anomalous Hall effect in type-II conventional and high-Tc superconductors
Directional vortex pinning at microwave frequency in YBa$_{2}$Cu$_3$O$_{7-x}$ thin films with BaZrO$_3$ nanorods
研究了用脉冲激光烧蚀法从含5%（摩尔分数）BaZrO $_3$的靶上生长的YBaPDMATHABMM CuPDMATHABMN O $_{7-x}$薄膜的各向异性和定向钉扎效应. BaZrO $_3$夹杂物自组装得到沿c轴取向的纳米棒，从而为涡旋钉扎提供了优先方向。涡旋响应的方向性研究在高交流频率与复杂的微波响应在48 GHz，作为一个功能的应用领域和领域和c轴之间的角度$θ$。复杂的微波响应不表现出任何角度缩放，这表明YBa $_2$ Cu $_3$ O $_{7-x}$的结构各向异性的补充，至少另一个优选的取向。钉扎参数$r$显示定向钉扎的证据，在围绕c轴的宽范围的角度中有效（因此归因于BZO纳米柱）。
Directional pinning and anisotropy in YBa2Cu3O7-x with BaZrO3 nanorods: intrinsic and nanorods-induced anisotropy
研究了在倾斜磁场作用下，含BaZrO 3纳米棒的YBa 2 Cu 3 O 7-x薄膜在涡旋态下的微波复电阻率.给出了涡旋粘性$η$、钉扎常数k_p和蠕变因子χ_M的上限随角度的变化关系。我们发现，纳米棒的方向效应在η中是不存在的，这是由质量各向异性γ决定的。相比之下，钉扎介导的性质受到纳米棒的强烈影响。重要的是，受纳米棒影响的钉扎和蠕变在我们非常高的工作频率下也是可检测的，这意味着涡旋从其平衡位置的非常短的位移。
Anisotropy and directional pinning in YBaCuO with BaZrO3 nanorods
在YBa $_2$ Cu $_3$ O $_{7-x}$与细长的强钉扎位点（c轴对齐，自组装BaZrO $_3$纳米棒）的驱动涡旋物质的各向异性输运性质（直流和高频制度）的测量被用来证明，有效质量角标度只发生在本征物理量（磁通流电阻率），而不是钉扎相关的Labusch参数和临界电流。在不同的时间尺度上的动力学比较显示的证据的涡旋物质向莫特相的过渡，由纳米棒的存在下驱动。强钉扎在直流部分来自动态效应。
Field-Free Superconducting Diode Enabled by Geometric Asymmetry and Perpendicular Magnetization
Beihang University（北京航空航天大学）；Beijing Superstring Academy of Memory Technology（北京超弦存储技术研究院）；Toyota Riken-Kyoto University Research Center (TRiKUC)（丰田理研京都大学研究中心）；Qingdao Research Institute, Beihang University（北京航空航天大学青岛研究院）
