Roy A, Wu Y, Berkovits R, Frydman A
Department of Physics, Jack and Pearl Resnick Institute the and Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 52900, Israel.
Phys Rev Lett. 2020 Oct 2;125(14):147002. doi: 10.1103/PhysRevLett.125.147002.
The Aharonov-Casher effect is the analogue of the Aharonov-Bohm effect that applies to neutral particles carrying a magnetic moment. This effect can be manifested by vortices or fluxons flowing in trajectories that encompass an electric charge. These vortices have been predicted to result in a persistent voltage that fluctuates for different sample realizations. Here, we show that disordered superconductors exhibit reproducible voltage fluctuation, which is antisymmetrical with respect to the magnetic field, as a function of various parameters such as the magnetic field amplitude, field orientations, and gate voltage. These results are interpreted as the vortex equivalent of the universal conductance fluctuations typical of mesoscopic disordered metallic systems. We analyze the data in the framework of random matrix theory and show that the fluctuation correlation functions and curvature distributions exhibit behavior that is consistent with Aharonov-Casher physics. The results demonstrate the quantum nature of the vortices in highly disordered superconductors, both above and below T_{c}.
阿哈罗诺夫 - 卡什效应是阿哈罗诺夫 - 玻姆效应的类似物，适用于携带磁矩的中性粒子。这种效应可以通过在围绕电荷的轨迹中流动的涡旋或磁通子表现出来。这些涡旋预计会导致一个持续电压，该电压会因不同的样品实现而波动。在这里，我们表明无序超导体表现出可重复的电压波动，它作为诸如磁场幅度、场方向和栅极电压等各种参数的函数，相对于磁场是反对称的。这些结果被解释为介观无序金属系统中典型的普遍电导涨落的涡旋等效物。我们在随机矩阵理论的框架内分析数据，并表明涨落相关函数和曲率分布表现出与阿哈罗诺夫 - 卡什物理一致的行为。结果证明了在高于和低于临界温度(T_{c})时，高度无序超导体中涡旋的量子性质。
