Magnetic flux quantization in superconductors allows the implementation of fast and energy-efficient digital superconducting circuits. However, information representation in magnetic flux severely limits the functional density and is a long-standing problem. Here, we introduce the concept of superconducting digital circuits that do not utilize magnetic flux and have no inductors. We argue that neither the use of geometric nor kinetic inductance is promising for the scaling down of superconducting circuits. The key idea of our approach is the utilization of bistable Josephson junctions, allowing the representation of information through the Josephson energy. Since the proposed circuits are composed only of Josephson junctions, they can be called all-Josephson junction (all-JJ) circuits. We present a methodology for the design of circuits consisting of conventional and bistable junctions. We analyze the principles of the circuit’s functioning, ranging from simple logic cells to an 8-bit parallel adder. The utilization of bistable junctions in the all-JJ circuits is promising for the simplification of schematics and a decrease of the JJ count, leading to space efficiency.

中文翻译：

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基于双稳态约瑟夫森结的无电感超导电路

超导体中的磁通量量化允许实现快速且节能的数字超导电路。然而，磁通量中的信息表示严重限制了功能密度，并且是一个长期存在的问题。在这里，我们介绍不利用磁通量且没有电感器的超导数字电路的概念。我们认为，无论是几何电感还是动力学电感的使用都不利于超导电路的按比例缩小。我们方法的关键思想是利用双稳态约瑟夫森结，允许通过约瑟夫森能量表示信息。由于所提出的电路仅由约瑟夫森结组成，因此它们可以称为全约瑟夫森结（all-JJ）电路。我们提出了一种设计由传统和双稳态结组成的电路的方法。我们分析了电路功能的原理，从简单的逻辑单元到 8 位并行加法器。在全 JJ 电路中使用双稳态结有利于简化原理图和减少 JJ 数量，从而提高空间效率。