BSCCO固有ジョセフソン接合におけるマイクロ波誘起ステップの発生機構

抄録

A mechanism producing microwave-induced steps crossing the zero-current axis of I-V characteristics of Bi₂Sr₂CaCu₂O_8+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-T_c 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.