Dissipative-free electric current flow is one of the most fascinating and practically important properties of superconductors. Theoretical consideration of the charge carriers flow in infinitely long rectangular slab of superconductor in the absence of external magnetic field (so called, self-field) is based on an assumption that the charge carriers have rectilinear trajectories in the direction of the current flow whereas the current density and magnetic flux density are decaying towards superconducting slab with London penetration depth as characteristic length. Here, we calculate charge particle trajectories (as single electron/hole, as Cooper pair) at self-field conditions and find that charge carriers do not follow intuitive rectilinear trajectories along the slab surface, but instead ones have meander shape trajectories cross the whole thickness of the slab. Moreover, if the particle velocity is below some value, the charge moves in opposite direction to nominal current flow. This disturbance of the canonical magnetic flux density distribution and backward movement of Cooper pairs can be entire mechanism for power dissipation in superconductors.

中文翻译：

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自场条件下超导板中的库珀对轨迹

无耗散电流是超导体最迷人和最重要的特性之一。在没有外部磁场（所谓的自场）的情况下，电荷载流子在无限长的矩形超导体板中流动的理论考虑是基于电荷载流子在电流方向上具有直线轨迹的假设，而电流密度和磁通密度正朝着以伦敦穿透深度为特征长度的超导板衰减。在这里，我们计算了自场条件下的电荷粒子轨迹（作为单个电子/空穴，作为库珀对），并发现电荷载流子不沿着平板表面遵循直观的直线轨迹，但取而代之的是曲折形状的轨迹穿过板的整个厚度。此外，如果粒子速度低于某个值，则电荷会以与标称电流相反的方向移动。这种对标准磁通密度分布的扰动和库珀对的向后运动可能是超导体中功率耗散的整个机制。