Microwave-induced effects on collective vortex motion in Bi-2212 intrinsic Josephson junction stacks

Abstract

Microwave responses of intrinsic Josephson junction stacks in the flux-flow state have been studied to explore phase-locked vortex motion. Remarkable step and zero-crossing structures are induced in the I–V characteristics by microwave irradiations. It is shown that vortex motion phase-locked to external microwaves plays an important role in the responses. Numerical simulations reveal that the alternating magnetic field of microwaves drives vortices into the stack and generates the zero-crossing step.