论文标题
观察$ nd_ {0.8} sr_ {0.2} nio_ {3-Δ} $的氧不足的镍薄膜中类似约瑟夫森的隧道连接特性和阳性磁磁性
Observation of Josephson-like tunneling junction characteristics and positive magnetoresistance in Oxygen deficient Nickelate films of $Nd_{0.8}Sr_{0.2}NiO_{3-δ}$
论文作者
论文摘要
由于观察到$ nd_ {0.8} sr_ {0.2} nio_2 $的无限层相中的超导相位，镍膜最近引起了广泛的关注（通过减少SR掺杂$ NDNIO_3 $膜，它们与Cuprates高温超级导管相似。在这里，我们报告了观察氧气差$ nd_ {0.8} sr_ {0.2} nio_ {3-δ} $胶片中一种新型的运输类型。在高温下，观察到可变范围跳跃，而在低温下，发现新型的隧道行为，而在揭示了具有串行电阻的约瑟夫森样隧道连接特征。我们将这种现象归因于我们氧较差膜中晶粒的超导（s）通过绝缘（I）晶界的耦合，该晶粒边界与晶粒本身的正常（n）抗性产生SIS连接。观察到的电导光谱与隧道连接特征与约瑟夫森般的电流的相似性令人震惊，并且似乎支持我们的样品中超导性的存在。
Nickelate films have recently attracted broad attention due to the observation of superconductivity in the infinite layer phase of $Nd_{0.8}Sr_{0.2}NiO_2$ (obtained by reducing Sr doped $NdNiO_3$ films) and their similarity to the cuprates high temperature superconductors. Here we report on the observation of a new type of transport in oxygen poor $Nd_{0.8}Sr_{0.2}NiO_{3-δ}$ films. At high temperatures, variable range hopping is observed while at low temperatures a novel tunneling behavior is found where Josephson-like tunneling junction characteristic with serial resistance is revealed. We attribute this phenomenon to coupling between superconductive (S) surfaces of the grains in our Oxygen poor films via the insulating (I) grain boundaries, which yields SIS junctions in series with the normal (N) resistance of the grains themselves. The similarity of the observed conductance spectra to tunneling junction characteristic with Josephson-like current is striking, and seems to support the existence of superconductivity in our samples.
