Use of a coherent-state formalism in superconductivity and Josephson-junction calculations

An investigation is made of the extent to which harmonic-oscillator coherent states can be used to describe superconductivity and Josephson tunneling phenomena. Recent work has utilized angular-momentum commutation relations for operators that create and annihilate pairs in a Josephson device. The formalism utilizes certain approximations in obtaining angular-momentum commutation rules for the superconducting tunnel junction. The coupled harmonic-oscillator approach due to Schwinger is applied to regain angular-momentum commutation relations