Flux-flow resonant current steps in intrinsic Josephson junctions on Bi2Sr2CaCu2O8 single crystal

A mesa with a-b plane dimensions of 12 mu m x 12 mu m was patterned on Bi2S r2CaCu2O8 Single crystal, after which two separate electrical contacts were carefully fabricated on the top of the mesa to ensure a standard four-prob e arrangement. With contact resistance excluded, the measured current-volta ge (I-V) curves featured high voltage resolution. Voltage jumps up to 20 mV and remarkable hysteresis at 4.2 K indicated typical superconductor-insula tor-superconductor properties. A few sharp current steps started to manifes t themselves clearly when a magnetic field of about 10 kOe was applied para llel to the a-b plane. Carefully studied were the dependences of the curren t steps on the magnetic fields and the operating temperatures. We attribute d the field-induced steps to the flux-flow resonances, and the multisteps i mplied different modes existing in the stacked intrinsic junctions. The vol tage region at which the steps occurred was of the order of millivolts, ind icating possible high-frequency applications at mm and sub-mm wavebands.