Superconductor–insulator transition in a single Josephson junction

Abstract

Resistively shunted, single Josephson junctions are studied theoretically. The method complements the band picture and is aimed at the superconductor–insulator transition regime in the E J /E C , R q /R plane, where E J and E C are the Josephson energy and the charging energy E C= e 2/2 C, C being the capacitance of the junction and R q= h/4 e 2 and R are the quantum resistance and the shunt resistance. The I– V characteristic is formulated by a new theory and evaluated by the path-integral transfer matrix method. The obtained result is in accordance with the recent experiments.