Quantum Interference and Critical Currents of Superconduct- ive Microcircuits Without Josephson Junctions

虽然大多数用于小规模应用的超导电路使用约瑟夫森结作为有源或开关元件，但在一些重要的情况下，约瑟夫森结应该被尺寸与温度相关的相干长度E(T)大小的简单细线所取代。研究人员正在从理论上研究微电路的可行性，这种电路在许多方面都可以像超导量子干涉装置(SQUID)电路那样运行，而不使用约瑟夫森结。这种装置可以通过超导回路来制造，超导回路的直径是相干长度的数量级，并且在相对的两侧连接超导导线以注入外部控制电流。磁通量B垂直于环施加。磁通密度产生循环电流。对于不同注入的控制电流，循环电流密度将作为磁通的函数进行研究，这些结果将被推广到更复杂的电路，如有限和无限大的梯形电路和阵列。

Although most superconducting circuits employed for small-scale applications use Josephson conjunctions as an active or switching element, in some important instances Josephson junctions should be replaceable by simple thin wires whose dimensions are of the size of the temperature-dependent coherence length, E(T). The researchers are studying theoretically the feasibility of a microcircuit which may behave in many respects like a SQUID (superconducting quantum interference device) circuit without the use of Josephson junctions. This device may be fabricated by means of a superconducting loop whose diameter is of the order of magnitude of the coherence length and has connected to it on opposite sides superconducting wires for the purpose of injecting an external control current. Magnetic flux B is applied perpendicular to the ring. The flux density gives rise to a circulating current. The circulating current density will be studied as a function of magnetic flux for various injected control currents, and these results will be extended to more complicated circuits such as finite and infinite ladder circuits and arrays.