Dynamics of microwave-induced fluxons in HgI2-intercalated Bi2Sr2CaCu2O8+delta Josephson stacks

The microwave response of intrinsic Josephson junctions (IJJs) in mesa structures formed on HgI2-intercalated Bi2Sr2CaCu2O8+delta single crystals was studied in a range of microwave frequencies above the junction plasma frequency. Under 73-76 GHz microwave irradiation, the supercurrent branch becomes resistive above a certain onset microwave power. At a low current bias, the current-voltage characteristics show linear behavior, while at a high current bias, the resistive branch splits into multiple sub-branches. The voltage spacing between neighboring sub-branches increases with the microwave power and the total number of sub-branches is almost identical to the number of IJJs in the mesa. All the experimental results suggest that each sub-branch represents a specific mode of collective motion of Josephson vortices generated by the microwave irradiation in a stack of IJJs. (C) 2001 Elsevier Science B.V. All rights reserved.X111sciescopu