YBa_2Cu_3 O_{7-δ} /Au/Nb斜锯齿形约瑟夫森结临界电流与磁场的关系
Magnetic field dependence of the critical current in YBa_2Cu_3O_{7-δ}/Au/Nb ramp-zigzag Josephson junctions
摘要：
本文研究了YBa_2Cu_3 O_{7-δ} -Nb多面斜坡型锯齿形约瑟夫森结的临界电流I_c与外加磁场H的关系。对于许多实验，人们希望在结平面上施加均匀场。然而，即使是微小的错位也会导致严重的同质性偏差。我们通过测量和分析8个小平面结的I_c与H的关系明确地表明了这一点，形成了4个\times（0-π）段的阵列。斜坡角度为θ_r=8^ \circ。刻面宽度为10 μ m，\mum。在相对于衬底平面的不同角度θ和相对于双金属标签的平面内取向的不同角度θ下施加H。我们发现，只有当θ_h为\approx 1^ \circ - 2^ \circ时，才能得到均匀的磁通分布，而且即使\sim 0.1^ \circ相对于θ_h有很小的不对准，也会引起结内磁通密度的显著不均匀，从而大大改变其I_c与H的干涉图样。我们还指出，存在一个相对于θ_h大小相近的死角θ^*_d，在此平均通量密度完全为零。
英文摘要：
We study the critical current I_c dependence on applied magnetic field H for multifacet YBa_2Cu_3O_{7-δ}-Au-Nb ramp-type zigzag Josephson junctions. For many experiments one would like to apply a homogeneous field in the junction plane. However, even tiny misalignments can cause drastic deviations from homogeneity. We show this explicitly by measuring and analyzing I_c vs. H for an 8 facet junction, forming an array of 4\times(0-π)-segments. The ramp angle is θ_r=8^\circ. The facet width is 10\,\mum. H is applied under different angles θrelative to the substrate plane and different angles ϕrelative to the in-plane orientation of the zigzags. We find that a homogeneous flux distribution is only achieved for an angle θ_h\approx 1^\circ - 2^\circ and that even a small misalignment \sim 0.1^\circ relative to θ_h can cause a substantial inhomogeneity of the flux density inside the junction, drastically altering its I_c vs. H interference pattern. We also show, that there is a dead angle θ^*_d relative to θ_h of similar magnitude, where the average flux density completely vanishes.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
