Microwave phase locking steps in intrinsic Josephson junctions of Bi2Sr2CaCu2Oy single crystals

The microwave-induced phase-locking phenomena in the intrinsic Josephson junctions in Bi2Sr2CaCu2Oy single crystal mesas have been investigated experimentally. For the mesas with the dimensions much larger than the Josephson penetration depth, obvious microwave-induced steps composed of fundamental and subharmonic steps have been successfully observed in the current-voltage characteristics. The voltages of both steps increase proportionally to the microwave power, and the amplitudes of the subharmonic steps show periodical change with the microwave frequency. These dynamical properties can be interpreted to be caused by the microwave-induced phase-locking fluxon motion in the intrinsic Josephson junctions. (C) 1997 Elsevier Science B.V.