High-Temperature Superconductor Diode Devices Prepared with Nano-Fabrication Technique

我们研究了基于高温超导薄膜的非对称纳米桥。预期ANB在高频下充当整流器。ANB在其几何形状中具有“K”形状。Abrikosov涡只能在收缩边缘进入ANB，因此在ANB处出现棘轮效应。在适当的磁场下，棘轮效应导致ANB的临界电流降低。我们调查的幅度的临界电流减少不同的膜厚度和不同宽度的ANB。实验结果表明，有效侵彻深度是决定ANB性能的关键参数。我们还准备了由两个ANB组成的SQUID。我们已经观察到，当我们增加施加的磁场时，在SQUID上产生的电压的长期调制以及周期性调制。虽然没有观察到临界电流的大调制深度，但这一结果表明，在优化电路参数后，将获得大幅度的降低。

We have studied on asymmetrical nano-bridges (ANBs) based on high-temperature superconducting films. The ANBs are expected to be act as a rectifier at high frequencies. The ANBs have "K" shapes in their geometry. Abrikosov vortices can enter the ANBs only at the constricted edges, so that the Ratchet effect appears at ANBs. The Ratchet effect leads to the reduction of the critical currents of ANBs under appropriate magnetic fields. We investigate the magnitude of the critical current reduction for different film thicknesses and different widths of ANBs. Experimental results show that the effective penetration depth is a key parameter to determine the characteristics of the ANBs. We also prepare SQUIDs consisting of two ANBs. We have observed long-term modulations in voltages generated across the SQUIDs together with periodic modulations when we increase applied magnetic fields. Although the large modulation depth of critical currents have not been observed, this result suggests that large reduction would be obtained afteroptimization of the circuit parameters.