Producing Mechanism of Microwave-induced Steps observed in BSCCO Intrinsic Josephson Junctions

Abstract

A mechanism producing microwave-induced steps crossing the zero-current axis of I-V characteristics of Bi2Sr2CaCu2O8+x (BSCCO) intrinsic Josephson Junctions under a microwave irradiation was investigated by a numerical simulation. On the basis of both inductive and charge coupling effects in high-Tc superconductors, the numerical simulation using the coupled sine-Gordon equations for 13 intrinsic Josephson junctions was performed under 5- and 20-GHz microwave irradiation without a dc bias current. The simulation demonstrated an ac Josephson current with a harmonic frequency of the microwave and a dc voltage induced by the current. This implies that the microwave-induced steps are not produced by a flux flow but originate from the inverse ac Josephson effect produced by the current with the harmonic frequency.