标题： 横向交流驱动和几何整流效应在共形晶格钉扎阵列中的涡旋效应 显示英文标题

标题： Transverse ac Driven and Geometric Ratchet Effects for Vortices in Conformal Crystal Pinning Arrays

摘要： 通过一系列共形阵列，可以创建不对称的基底，并且之前已经表明，当交流驱动与不对称方向平行时，会出现显著的整流效应，导致涡旋的净直流流动方向与交流驱动方向相同。 在这里，我们展示了当交流驱动与基底不对称方向垂直时，可以实现横向整流效应，其中净直流涡旋流动方向与交流驱动方向垂直。 共形横向整流效应不同于以前的横向整流效应，因为它是由涡旋的塑性运动产生的非高斯横向涡旋速度波动引起的，因此系统表现为噪声相关整流器。 在共形阵列中，横向整流效应比在随机梯度阵列中更为明显，并且在方形梯度阵列中不存在，这是由于每种几何结构中涡旋流动的性质不同。 我们展示了由于涡旋填充、钉扎强度和交流幅度随涡旋流动变化而产生的反转现象，可以在横向整流效应中发生。 我们还考虑了当直流驱动垂直于基底不对称方向时，会产生一个垂直于直流驱动的涡旋净流动，产生一种几何或漂移整流效应，这种效应是由于动态产生的非高斯波动引起的。 漂移整流效应比交流驱动整流效应更有效，并且在参数变化时也表现出一系列反转。 我们的结果应适用于在共形基底上进行非平衡动力学的广泛系统，例如光学陷阱上的胶体粒子。 显示英文摘要

摘要： With a series of conformal arrays it is possible to create asymmetric substrates, and it was previously shown that when an ac drive is applied parallel to the asymmetry direction, a pronounced ratchet effect occurs with a net dc flow of vortices in the same direction as the ac drive. Here we show that when the ac drive is applied perpendicular to the substrate asymmetry direction, it is possible to realize a transverse ratchet effect where a net dc flow of vortices is generated perpendicular to the ac drive. The conformal transverse ratchet effect is distinct from previous versions of transverse ratchets in that it occurs due to the generation of non-Gaussian transverse vortex velocity fluctuations by the plastic motion of vortices, so that the system behaves as a noise correlation ratchet. The transverse ratchet effect is much more pronounced in the conformal arrays than in random gradient arrays, and is absent in square gradient arrays due the different nature of the vortex flow in each geometry. We show that a series of reversals can occur in the transverse ratchet effect due to changes in the vortex flow across the pinning gradient as a function of vortex filling, pinning strength, and ac amplitude. We also consider the case where a dc drive applied perpendicular to the substrate asymmetry direction generates a net flow of vortices perpendicular to the dc drive, producing a geometric or drift ratchet that arises due to non-Gaussian dynamically generated fluctuations. The drift ratchet is more efficient than the ac driven ratchet and also exhibits a series of reversals for varied parameters. Our results should be general to a wide class of systems undergoing nonequilibrium dynamics on conformal substrates, such as colloidal particles on optical traps.