Numerical research on RF induced zero-crossing steps of stacked Josephson junction in flux-flow state

► We had experimented on RF effects on flux-flow of intrinsic Josephson junctions. ► In a pinning free state, a remarkable zero-crossing step appears on I-V curve. ► We carried out numerical simulation to compare with the experimental results. ► The induced RF drives vortices and generates the zero-crossing step. ► The zero-crossing step is generated by the vortex motion phase-locked to induced RF.