Mode locking features of driven vortex matter in an amorphous MoGe film detected by rf impedance technique

摘要: We have investigated mode locking resonance of a driven vortex lattice in an amorphous MoGe film by means rf impedance measurements. This technique allows us to detect directly the motion response current superimposed on top dc current. At low currents appears as jumps (dips) real (imaginary) part Z. On increasing current, jump height Z at given resonant condition decreases monotonically, whereas imaginary exhibits transformation from dip peak behaviors. Namely, feature changes capacitive inductive responses, behavior implies variations phase relative that velocity modulated pinning potential.