论文标题
无环形超导网络中的量子相干性
Quantum Coherence in Loopless Superconductive Networks
论文作者
论文摘要
测量表明，约瑟夫森连接连接的超导岛的平面网络显示了远程量子相干性。网络由约瑟夫森连接连接的超导岛组成，并具有包含循环的树状拓扑结构。超导差距在网络的特定分支上的增强和配对电流的急剧增加是相干状态的主要签名，为了明确地将观察到的效果归因于网络中的分支，与几何相等的相等，据报道，但据报道，孤立的，对立面。通过外部磁场来调整约瑟夫森耦合能，会沿上述特定分支产生约瑟夫森电流的增加，该分支遵循相变的功能依赖性。为双梳和恒星几何网络提供了结果，在这两种情况下，观察到的效果都提供了现有理论模型预测的积极定量证据。
Measurements indicating that planar networks of superconductive islands connected by Josephson junctions display long range quantum coherence are reported. The networks consist of superconducting islands connected by Josephson junctions and have a tree-like topological structure containing no loops. Enhancements of superconductive gap over specific branches of the networks and sharp increases of pair currents are the main signatures of the coherent states and, in order to unambiguously attribute the observed effects to branches being embedded in the networks, comparisons with geometrically equivalent, but isolated, counterparts are reported. Tuning the Josephson coupling energy by an external magnetic field generates increases of the Josephson currents, along the above mentioned specific branches, which follow a functional dependence typical of phase transitions. Results are presented for double comb and star geometry networks and in both cases the observed effects provide positive quantitative evidence of the predictions of existing theoretical models.
