Gurevich A, Vinokur V M
National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, USA.
Phys Rev Lett. 2008 Jun 6;100(22):227007. doi: 10.1103/PhysRevLett.100.227007.
We show that the size effects radically affect the electric-field-current (E-I) relation of superconducting films. We calculate E(J) due to thermally activated hopping of single vortices driven by a current I across the film in a magnetic field H, taking into account the interaction of free vortices with their antivortex images and peaks in the Meissner currents at the film edges. The unbinding of the virtual vortex-antivortex pairs not only mimics the transport uniform Berezinskii-Kosterlitz-Thouless behavior, it can also dominate the observed E(J) and result in the field-dependent Ohmic resistance at small I. We show that E(I) can be tuned by changing the film geometry and propose experimental tests of this theory.
我们表明，尺寸效应会从根本上影响超导薄膜的电场-电流（E-I）关系。我们计算了在磁场H中，由电流I驱动的单个涡旋热激活跳跃所产生的E(J)，该电流I穿过薄膜，同时考虑了自由涡旋与其反涡旋镜像的相互作用以及薄膜边缘迈斯纳电流的峰值。虚拟涡旋-反涡旋对的解离不仅模拟了均匀的贝雷津斯基-科斯特利茨- Thouless输运行为，还能主导观测到的E(J)，并在小电流I时导致与场相关的欧姆电阻。我们表明，可以通过改变薄膜几何形状来调节E(I)，并提出了该理论的实验测试。
