Physics and Devices of Superconductive Electronics

In this chapter, the phenomenon of superconductivity is introduced. A theoretical framework for the analysis of low-temperature superconductive materials—the London, Ginzburg-Landau, and Bardeen-Cooper-Schrieffer theories—is described. The defining features of superconductive materials are discussed, along with different types of materials and characteristics. The properties of these materials are emphasized in relation to superconductive electronics. As compared to conventional transistor-based circuits, superconductive electronics utilize a different set of basic devices as building blocks of larger circuits. These basic devices are introduced in this chapter. The properties and dynamic behavior of Josephson junctions are discussed with intuitive analogies describing both the dynamic behavior and classic circuit models. Important cryogenic devices commonly used in superconductive electronics are also briefly reviewed.