Josephson Tunneling Current in Spin Polaron Theory

Abstract

Using an effective Hamiltonian derived from spin polaron theory, the Josephson tunneling current between two high temperature superconductors is calculated. The method makes use of the Matsubara Green’s function and a canonical transformation analogous to the Schrieffer–Wolff transformation. The Josephson tunneling current is then obtained in terms of the energy gap function and the tunneling matrix, and it was found to have some similarities with the BCS result.