Josephson Junctions Using Polyimide Langmuir-Blodgett Films with a Nb/Au/PI/(Pb-Bi) Structure

Abstract

We fabricated Josephson junctions with the structure of Nb/Au/PI/(Pb-Bi) using an ultrathin polyimide (PI) Langmuir- Blodgett film as an electrically insulating layer with neither the presence of native oxide layers formed on the base Nb layer nor the dissolution of the base-Nb/Au electrode during the imidization of PAA (Polyamic acid long alkylamine salts) films to produce PI LB films. A typical I - V characteristic of weakly-coupled Josephson junctions was found to be obtained.