Josephson junction array structure, digital-to-analog converter and superconducting voltage standard circuit using the structure

摘要

PROBLEM TO BE SOLVED: To solve the problem in a Josephson junction array structure that since operation margin considerably decreases when the number of junctions is increased, the output voltage of a superconducting digital to analog converter is low by preventing reduction in an operation margin due to high degree of integration and heat generation in a Josephson junction array structure with as high impedance as 100 Ω.;SOLUTION: A Josephson junction array structure of the present invention comprises a Josephson junction array and an external conductor disposed on both sides thereof. The Josephson junction array is such that two adjacent Josephson junctions are connected sharing one bottom electrode, and that the bottom electrode includes a wide part extending from the Josephson junction to the external conductor and a narrow part at a position where the adjacent Josephson junctions are connected. The bottom electrode having the narrow part and sufficiently large in size helps to achieve a high line impedance, making it possible to restrict the attenuation of an electromagnetic pulse signal due to junction resistance.;COPYRIGHT: (C)2013,JPO&INPIT